#!/usr/local/bin/perl -w     # for Solaris.
#
#!/usr/bin/perl -w           # for Linux.
#
#use strict;
#use blib;
#
###############################################################################
#
# GS_SEARCH - Search on-line catalogs for NIFS wave front sensor guide stars.
#
# Copyright   Peter J. McGregor
#
# Research School of Astronomy and Astrophysics
# Institute of Advanced Studies
# Australian National University
#
# Usage: ./gs_search [-df] file_name
#
#        -d  Display on screen.
#        -p  Generate postscipt file.
#        -g  Generate gif file.
#        -f  Force reacquisition of image files.
#        -n  Report NGS and LGS Y,?,N statistics.
#
# Requires PGPerl from http://www.aao.gov.au/local/www/kgb/pgperl/ and
# CFITSIO.pm from http://hea-www.harvard.edu/~rpete/cfitsio/.
#
# Modification history:
#
# 24-OCT-00  PJM  Creation.
# 05-DEC-00  PJM  Added -n command line option.
# 17-JAN-01  PJM  Added g cursor option to overlay FOV grid.
# 18-JAN-01  PJM  Fixed bug in cursor position of magnitude measurement.
#
###############################################################################

# Include packages.

use IO::Socket;
use CFITSIO qw( :longnames );
use PGPLOT;

# Define constants.

$rlim = 19.0;

# Check if environment variables are defined.

if ($ENV{'PRINTER'} eq "") {
    $printer = "";
} else {
    $printer = $ENV{'PRINTER'};
}

# Define initial values (1 = .true.).

$dcod = 0;
$pcod = 0;
$gcod = 0;
$fcod = 0;
$ncod = 0;
$but_title_1_sta = 0;
$but_title_2_sta = 0;
$but_title_3_sta = 0;
$but_title_4_sta = 0;
@ngs = (0,0,0);
@lgs = (0,0,0);

# Read data file name from command line.

if ($#ARGV < 0) {
    die "GS_SEARCH.PL: Usage: ./gs_search.pl [-df] file_name\n".
        "                     -d  Display on screen.\n".
        "                     -p  Generate postscript file.\n".
        "                     -g  Generate gif file.\n".
        "                     -f  Force reacquisition of image files.\n".
        "                     -n  Report NGS and LGS Y,?,N statistics.\n";
} elsif ($#ARGV == 0) {
    ($lis) = @ARGV;
} elsif ($#ARGV == 1) {
    ($cmd,$lis) = @ARGV;
    if (substr($cmd,0,1) ne "-") {
	die "GS_SEARCH.PL: Invalid command line arguments!\n";
    } else {
	$cmd = substr($cmd,1);
    }
    while ($cmd ne "") {
        $cod = substr($cmd,0,1);
        if ($cod eq "d") {
	    $dcod = 1;              # .true.
	} elsif ($cod eq "p") {
	    $pcod = 1;              # .true.
	} elsif ($cod eq "g") {
	    $gcod = 1;              # .true.
	} elsif ($cod eq "f") {
	    $fcod = 1;              # .true.
	} elsif ($cod eq "n") {
	    $ncod = 1;              # .true.
	} else {
	    die "GS_SEARCH.PL: Invalid command line options!\n";
	}
	$cmd = substr($cmd,1);
    }
} else {
    die "GS_SEARCH.PL: Too many command line arguments!\n";
}

# Open list file and loop through entries.

open (LIS,"$lis") or die "GS_SEARCH.PL: Cannot open list file $lis.\n";

while (<LIS>) {

    # Skip comment lines.

    $str = substr($_,0,1);
    if ($str eq "#") {
	next;
    }

    # Form object and file names.

    chomp;
    $obj = substr($_, 0,15); 
    $fil = lc($obj); $fil =~ s/\s{1}//g;
    if (length > 39) {
	$str = substr($_,16,23);
        if ($str eq "                       ") {$str = "";}
    } else {
	$str = "";
    }

    # Accumulate NGS and LGS statistics.

    if (substr($_,45,1) eq "Y" or substr($_,45,1) eq "y") {
	$ngs[0] += 1;
    } elsif (substr($_,45,1) eq "?") {
	$ngs[1] += 1;
    } elsif (substr($_,45,1) eq "N" or substr($_,45,1) eq "n") {
	$ngs[2] += 1;
    }
    if (substr($_,47,1) eq "Y" or substr($_,47,1) eq "y") {
	$lgs[0] += 1;
    } elsif (substr($_,47,1) eq "?") {
	$lgs[1] += 1;
    } elsif (substr($_,47,1) eq "N" or substr($_,47,1) eq "n") {
	$lgs[2] += 1;
    }

    # Create image directories.

    if (! -d "images")      {mkdir ("images",0777);}
    if (! -d "images/$fil") {mkdir ("images/$fil",0777);}

    # Read object data file if present. Otherwise, get on-line images

    unless (Read_Data($fil) and ! $fcod) {

	print "$obj";

	$col_tab = 1;
	$col_con = 0.1;
	$col_bri = 0.5;

	$dat_dss2_got   = 0;
	$dat_2mass_got  = 0;
	$dat_wfpc2_got  = 0;
	$dat_nicmos_got = 0;
	$dat_usno_got   = 0;

	$dat_aowfs_got = 0;
	$dat_aowfs_ra  = -100; $dat_aowfs_dec = -100;
	$dat_oiwfs_got = 0;
	$dat_oiwfs_ra  = -100; $dat_oiwfs_dec = -100;

	$ima_dss2_x_off    = 0; $ima_dss2_y_off    = 0;
	$ima_dss2_x_zoom   = 1; $ima_dss2_y_zoom   = 1;
	$ima_dss2_min      = 1; $ima_dss2_max      = 0;
	$ima_dss2_grid     = 0; $ima_dss2_grot     = 0;
	$ima_2mass_x_off   = 0; $ima_2mass_y_off   = 0;
	$ima_2mass_x_zoom  = 1; $ima_2mass_y_zoom  = 1;
	$ima_2mass_min     = 1; $ima_2mass_max     = 0;
	$ima_2mass_grid    = 0; $ima_2mass_grot    = 0;
	$ima_wfpc2_x_off   = 0; $ima_wfpc2_y_off   = 0;
	$ima_wfpc2_x_zoom  = 1; $ima_wfpc2_y_zoom  = 1;
	$ima_wfpc2_min     = 1; $ima_wfpc2_max     = 0;
	$ima_wfpc2_grid    = 0; $ima_wfpc2_grot    = 0;
	$ima_nicmos_x_off  = 0; $ima_nicmos_y_off  = 0;
	$ima_nicmos_x_zoom = 1; $ima_nicmos_y_zoom = 1;
	$ima_nicmos_min    = 1; $ima_nicmos_max    = 0;
	$ima_nicmos_grid   = 0; $ima_nicmos_grot   = 0;

	# Resolve object name if necessary.

	if ($str eq "") {
	    # Use NED to resolve object name.
	    Get_NED_Coords($obj,$ra,$dec);
	} else {
	    $rh  = substr($_,16, 2); $rh =~ s/\s{1}/0/g;
	    $rm  = substr($_,19, 2); $rm =~ s/\s{1}/0/g;
	    $rs  = substr($_,22, 5); $rs =~ s/\s{1}/0/g;
	    $dc  = substr($_,28, 1); $dc =~ s/\s{1}/+/g;
	    $dd  = substr($_,29, 2); $dd =~ s/\s{1}/0/g;
	    $dm  = substr($_,32, 2); $dm =~ s/\s{1}/0/g;
	    $ds  = substr($_,35, 4); $ds =~ s/\s{1}/0/g;
	    $ra  = "$rh:$rm:$rs";
	    $dec = "$dc$dd:$dm:$ds";
	}

	print " $ra $dec\n";

	# Get 3'x3' DSS-2 red image.
	
	Get_DSS2_Red($fil,$ra,$dec);

	# Get 3'x3' 2MASS K image.

	Get_2MASS_K($fil,$ra,$dec);

	# Get optimal WFPC2 image.

	Get_WFPC2($fil,$ra,$dec);

	# Get optimal NICMOS K image.

	Get_NICMOS($fil,$ra,$dec);

	# Get USNO catalog stars.

	Get_USNO($fil,$ra,$dec);

    }

#    if (! $dat_dss2_got) {
#	print "GS_SEARCH.PL: Attempting to retreived DSS-2 red image for $obj.\n";
#	# Get 3'x3' DSS-2 red image.
#	
#	Get_DSS2_Red($fil,$ra,$dec);
#
#    }

    $dat_dss2_read   = 0;
    $dat_2mass_read  = 0;
    $dat_wfpc2_read  = 0;
    $dat_nicmos_read = 0;

    $ima_dss2_sky = 0;
    $ima_2mass_sky = 0;
    $ima_wfpc2_sky = 0;
    $ima_nicmos_sky = 0;

    # Generate screen display.

    if ($dcod) {Display_Images($fil,$ra,$dec,1);}

    # Generate postscipt file.

    if ($pcod) {Display_Images($fil,$ra,$dec,2);}

    # Generate gif file.

    if ($gcod) {Display_Images($fil,$ra,$dec,3);}

    # Write object data file.

    Write_Data($fil);

}

close (LIS);

# Report NGS and LGS Y,?,N statistics.

if ($ncod) {
    print "\nGuide Star Statistics:\n";
    print "NGS system: Y=$ngs[0]; ?=$ngs[1]; N=$ngs[2]\n"; 
    print "LGS system: Y=$lgs[0]; ?=$lgs[1]; N=$lgs[2]\n\n";
}

exit;


# Routine to use NED to resolve object coordinates.

sub Get_NED_Coords {
    my ($obj) = @_; $obj =~ s/\s{1}//g;
    my ($host) = "archive.stsci.edu";
    my ($prompt) = "/cgi-bin/dss_form?target=$obj&resolver=NED";
    my ($EOL)  = "\015\012";
    my ($BLANK) = $EOL x 2;
    $remote = IO::Socket::INET->new( Proto     => "tcp",
				     PeerAddr  => $host,
				     PeerPort  => "http(80)"
				     );
    unless ($remote) {
	die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
    }
    $remote->autoflush(1);
    print $remote "GET $prompt HTTP/1.0" . $BLANK;
    while (<$remote>) {
        if (/name=r/) {
	    $ra = substr($_,index($_,"value=")+7,11);
	    $ra =~ s/\s{1}/:/g;
	}
        if (/name=d/) {
	    $dec = substr($_,index($_,"value=")+7,11);
	    $dec =~ s/\s{1}/:/g;
	}
    }
    close $remote;
    return;
}

# Routine to access DSS-2 red image.

sub Get_DSS2_Red {
    my ($fil,$ra,$dec) = @_;
    my ($fits) = "images/$fil/$fil"."_dss2_r.fits";
    if (! -f "$fits" or $fcod) {
	my ($ok) = 0;
	my ($host) = "archive.eso.org";
	my ($prompt) = "/dss/dss/image?ra=$ra&dec=$dec&equinox=J2000&x=3&y=3&Sky-Survey=DSS2-red&mime-type=download-fits";
	my ($EOL)  = "\015\012";
	my ($BLANK) = $EOL x 2;
	$remote = IO::Socket::INET->new( Proto     => "tcp",
					 PeerAddr  => $host,
					 PeerPort  => "http(80)"
					 );
	unless ($remote) {
	    die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	}
	$remote->autoflush(1);
	print $remote "GET $prompt HTTP/1.0" . $BLANK;
	while (<$remote>) {
	    if (/SIMPLE  =/) {
		open (OUT,">$fits") or 
		    die "GS_SEARCH.PL: Cannot open output file $fits!\n";
		$ok = 1;
	    }
	    if ($ok) {
		print OUT $_;
	    }
	}
	if ($ok) {
	    close (OUT);
	    $dat_dss2_got = 1;
	} else {
	    print "GS_SEARCH.PL: DSS2 red image for $fil is unavailable.\n";
	}
	close $remote;
    }
    return;
}

# Routine to access 2MASS K image.

sub Get_2MASS_K {
    my ($fil,$ra,$dec) = @_;
    my ($fits) = "images/$fil/$fil"."_2mass_k.fits";
    if (! -f "$fits" or $fcod) {
	$ra  =~ s/:/h/; $ra  =~ s/:/m/; $ra  = $ra."s";
	$dec =~ s/:/d/; $dec =~ s/:/m/; $dec = $dec."s";
        my ($ok, $prompt, $image, $overlay);
	my ($host) = "irsa.ipac.caltech.edu";
	my ($EOL)  = "\015\012";
	my ($BLANK) = $EOL x 2;
        # Request coadds.
	$remote = IO::Socket::INET->new( Proto     => "tcp",
					 PeerAddr  => $host,
					 PeerPort  => "http(80)"
					 );
	unless ($remote) {
	    die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	}
	$remote->autoflush(1);
	$prompt = "/cgi-bin/2MASS/ReleaseVis/nph-surveyvis?locstr=$ra+$dec+Equ+J2000&coadds=1&date=&hemisphere=&scan=&coadd=&show=coadd&coaddsize=180&band=K";
	print $remote "GET $prompt HTTP/1.0" . $BLANK;
        $ok = 0;
	while (<$remote>) {
	    if (/<b>Data:<\/b>/) {
		while (<$remote>) {
		    if (/href=/) {
			$image = substr($_,
					index($_,"href=")+6);
			$image = substr($image,
					0,
					index($image,">")-1);
			$ok = 1;
			# print "Image file $image\n";
			while (<$remote>) {
			    if (/href=/) {
				$overlay = substr($_,
						  index($_,"href=")+6);
				$overlay = substr($overlay,
						  0,
						  index($overlay,">")-1);
				# print "Overlay file $overlay\n";
			    }
			}
		    }
		}
	    }
	}
	close $remote;
        # Request FITS image.
	if ($ok) {
	    $remote = IO::Socket::INET->new( Proto     => "tcp",
					     PeerAddr  => $host,
					     PeerPort  => "http(80)"
					     );
	    unless ($remote) {
		die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	    }
	    $remote->autoflush(1);
	    print $remote "GET $image HTTP/1.0" . $BLANK;
	    $ok = 0;
	    while (<$remote>) {
		if (/SIMPLE  =/) {
		    open (OUT,">$fits") or 
			die "GS_SEARCH.PL: Cannot open output file $fits!\n";
		    $ok = 1;
		}
		if ($ok) {
		    print OUT $_;
		}
	    }
	    close $remote;
	}
	if ($ok) {
	    close (OUT);
	    $dat_2mass_got = 1;
	} else {
	    print "GS_SEARCH.PL: 2MASS K image for $fil is unavailable.\n";
	}
    }
    return;
}

# Routine to access WFPC2 image.

sub Get_WFPC2 {
    my ($fil,$ra,$dec) = @_;
    my ($fits) = "images/$fil/$fil"."_wfpc2.fits";
    if (! -f "$fits" or $fcod) {
	my ($ok, $prompt, $dataset, $score, $max_score); 
	my ($set, $sra, $sdec, $sep, $cen, $exp);
	my ($host) = "archive.stsci.edu";
	my ($EOL)  = "\015\012";
	my ($BLANK) = $EOL x 2;
        # Get dataset name.
	$remote = IO::Socket::INET->new( Proto     => "tcp",
					 PeerAddr  => $host,
					 PeerPort  => "http(80)"
					 );
	unless ($remote) {
	    die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	}
	$remote->autoflush(1);
	$prompt = "/cgi-bin/nph-hst?SEARCH_TYPE=none&target=&resolver=NONE&ra=$ra&dec=$dec&radius=1.0&equinox=J2000&obsdate=&exptime=&pi_name=&pep_id=&target_description=&dataset_name=&action=SEARCH&release_date=&archive_date=&bandwidth_type=Central+wavelength+falls+in+this+range+%28%C5+..+%C5%29%3A+&band=&output_cols=default&custom_output_columns=stdads_mark&sort1=ang_sep&sort2=sci_targname&sort3=sci_data_set_name&max_rows=100&output_equinox=J2000&imagers=WFPC2";
	print $remote "GET $prompt HTTP/1.0" . $BLANK;
	$ok = 0;
	$max_score = 0.1;
	while (<$remote>) {
	    if (/hst_preview_form/) {
		$score = 0.0;
		# Subset name.
		$set = substr($_,index($_,"?name=")+6);
		$set = substr($set,0,index($set,'"'));
		$_ = <$remote>;
                # RA.
		$sra  = substr($_,15,11); $sra =~ s/\s{1}/:/g;
		$_ = <$remote>;
                # Dec.
		$sdec = substr($_,15,12); $sdec =~ s/\s{1}/:/g;
		$_ = <$remote>;
		# Angular separation in arcmin.
		$sep = substr($_,29,index($_,"</TD>")-29);
		$score = $score+(1.0-$sep);
		$_ = <$remote>; 
		$_ = <$remote>;
		$_ = <$remote>;
		# Filter central wavelength in Angstroms.
		$cen = substr($_,29,index($_,"</TD>")-29);
		if ($cen == 7940.00) {            # F814W
		    $score += 15.0;
		} elsif ($cen == 7829.00) {       # F791W
		    $score += 12.0;
		} elsif ($cen == 6895.00) {       # F702W
		    $score += 11.0;
		} elsif ($cen == 6714.00) {       # F675W
		    $score += 10.5;
		} elsif ($cen == 6170.00) {       # F622W
		    $score += 10.0;
		} elsif ($cen == 5957.00) {       # F606W
		    $score += 9.00;
		} elsif ($cen == 5623.00) {       # F569W
		    $score += 1.00;
		} elsif ($cen == 5407.00) {       # F555W
		    $score += 0.90;
		} elsif ($cen == 4520.00) {       # F450W
		    $score += 0.50;
		} elsif ($cen == 4300.00) {       # F439W
		    $score += 0.40;
		} elsif ($cen == 3344.00) {       # F336W
		    $score += 0.10;
		} elsif ($cen == 2159.00) {       # F218W
		    $score += 0.01;
		} elsif ($cen == 9124.00) {       # F850LP
		    $score += 6.00;
		} elsif ($cen == 8674.00) {       # F785LP
		    $score += 5.00;
		} elsif ($cen == 10201.0) {       # F1042M
		    $score += 4.00;
		} elsif ($cen == 5479.00) {       # F547M
		    $score += 5.00;
		} elsif ($cen == 4669.00) {       # F467M
		    $score += 3.00;
		} elsif ($cen == 9534.00) {       # F953N
		    $score += 0.11;
		} elsif ($cen == 6800.00) {       # FR680N
		    $score += 0.10;
		} elsif ($cen == 6732.00) {       # F673N
		    $score += 0.10;
		} elsif ($cen == 6563.00) {       # F656N
		    $score += 0.20;
		} elsif ($cen == 6590.00) {       # F658N
		    $score += 0.10;
		} elsif ($cen == 6283.00) {       # F631N
		    $score += 0.09;
		} elsif ($cen == 5893.00) {       # F588N
		    $score += 0.05;
		} elsif ($cen == 5400.00) {       # FR533N
		    $score += 0.01;
		} elsif ($cen == 4200.00) {       # FR533N33
		    $score += 0.01;
		} elsif ($cen == 5013.00) {       # F502N
		    $score += 0.01;
		} elsif ($cen == 4866.00) {       # F487N
		    $score += 0.01;
		} elsif ($cen == 4694.00) {       # F469N
		    $score += 0.01;
		} elsif ($cen == 4369.00) {       # F437N
		    $score += 0.01;
		} elsif ($cen == 3737.00) {       # F375N
		    $score += 0.01;
		} elsif ($cen == 3424.00) {       # F343N
		    $score += 0.01;
		} elsif ($cen == 1523.00) {       # F160BW
		    $score += 0.00;
		} elsif ($cen  < 4000.00) {       # Anything blue
		    $score += 0.00;
		} elsif ($cen ==    0.00) {       # BLANK
		    $score += 0.00;
		} elsif ($cen == 4090.00) {       # Non-existant filter.
		    $score += 0.00;
		} else {
		    die "GS_SEARCH.PL: Unidentified WFPC2 filter $cen!\n";
		}
		$_ = <$remote>;
		# Exposure time in seconds.
		$exp = substr($_,29,index($_,"</TD>")-29);
		$exp = sprintf("%5.0f",$exp);
		$score = $score+$exp/1000.;
		$score = sprintf("%6.2f",$score);
		print "$obj $set $sra $sdec $sep $cen $exp $score\n";
		if ($score > $max_score) {
		    $max_score = $score;
		    $dataset = $set;
		    $ok = 1;
		}
	    }
	}
	close $remote;
	# Download dataset.
	if ($ok) {
	    # Retrieve dataset preview.
	    $remote = IO::Socket::INET->new( Proto     => "tcp",
					     PeerAddr  => $host,
					     PeerPort  => "http(80)"
					     );
	    unless ($remote) {
		die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	    }
	    $remote->autoflush(1);
	    $prompt = "/cgi-bin/hst_preview_search?name=$dataset&imfmt=fits&xfer=log&pc=off&shrink=off&ne=off";
	    print $remote "GET $prompt HTTP/1.0" . $BLANK;
	    $ok = 0;
	    while (<$remote>) {
		if (/SIMPLE  =/) {
		    open (OUT,">$fits") or 
			die "GS_SEARCH.PL: Cannot open output file $fits!\n";
		    $ok = 1;
		}
		if ($ok) {
		    print OUT $_;
		}
	    }
	    close $remote;
	}
	if ($ok) {
	    close (OUT);
	    $dat_wfpc2_got = 1;
	} else {
	    print "GS_SEARCH.PL: WFPC2 image for $fil is unavailable.\n";
	}
    }
    return;
}

# Routine to access NICMOS image.

sub Get_NICMOS {
    my ($fil,$ra,$dec) = @_;
    my ($fits) = "images/$fil/$fil"."_nicmos.fits";
    if (! -f "$fits" or $fcod) {
	my ($ok, $prompt, $dataset, $score, $max_score); 
	my ($set, $sra, $sdec, $sep, $cen, $exp);
	my ($host) = "archive.stsci.edu";
	my ($EOL)  = "\015\012";
	my ($BLANK) = $EOL x 2;
        # Get dataset name.
	$remote = IO::Socket::INET->new( Proto     => "tcp",
					 PeerAddr  => $host,
					 PeerPort  => "http(80)"
					 );
	unless ($remote) {
	    die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	}
	$remote->autoflush(1);
	$prompt = "/cgi-bin/nph-hst?SEARCH_TYPE=none&target=&resolver=NONE&ra=$ra&dec=$dec&radius=0.3&equinox=J2000&obsdate=&exptime=&pi_name=&pep_id=&target_description=&dataset_name=&action=SEARCH&release_date=&archive_date=&bandwidth_type=Central+wavelength+falls+in+this+range+%28%C5+..+%C5%29%3A+&band=&output_cols=default&custom_output_columns=stdads_mark&sort1=ang_sep&sort2=sci_targname&sort3=sci_data_set_name&max_rows=100&output_equinox=J2000&imagers=NICMOS";
	print $remote "GET $prompt HTTP/1.0" . $BLANK;
	$ok = 0;
	$max_score = 0.1;
	while (<$remote>) {
	    if (/hst_preview_form/) {
		$score = 0.0;
		# Subset name.
		$set = substr($_,index($_,"?name=")+6);
		$set = substr($set,0,index($set,'"'));
		$_ = <$remote>;
                # RA.
		$sra  = substr($_,15,11); $sra =~ s/\s{1}/:/g;
		$_ = <$remote>;
                # Dec.
		$sdec = substr($_,15,12); $sdec =~ s/\s{1}/:/g;
		$_ = <$remote>;
		# Angular separation in arcmin.
		$sep = substr($_,29,4);
		$score = $score+(1.0-$sep);
		$_ = <$remote>;
		$_ = <$remote>;
		$_ = <$remote>;
		# Filter central wavelength in Angstroms.
		$cen = substr($_,29); $cen =~ s\</TD>\\;
		$cen = sprintf ("%6.0f",$cen);
		if ($cen == 20714) {           # F205W, NIC2
		    $score = $score+15.0*2;
		} elsif ($cen == 18718) {      # F187W, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 18360) {      # F175W, NIC3
		    $score = $score+10.0*3;
		} elsif ($cen == 16071) {      # F160W, NIC1
		    $score = $score+10.0*1;
		} elsif ($cen == 16060) {      # F160W, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 16078) {      # F160W, NIC3
		    $score = $score+10.0*3;
		} elsif ($cen == 16071) {      # F160W, NIC1
		    $score = $score+10.0*1;
		} elsif ($cen == 15484) {      # F150W, NIC3
		    $score = $score+6.00*3;
		} elsif ($cen == 14399) {      # F140W, NIC1
		    $score = $score+6.00*1;
		} elsif ($cen == 11264) {      # F110W, NIC3
		    $score = $score+5.00*3;
		} elsif ($cen == 11285) {      # F110W, NIC2
		    $score = $score+5.00*2;
		} elsif ($cen == 11292) {      # F110W, NIC1
		    $score = $score+5.00*1;
		} elsif ($cen == 23696) {      # F237M, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 23969) {      # F240M, NIC3
		    $score = $score+10.0*2;
		} elsif ($cen == 23695) {      # F237M, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 22182) {      # F222M, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 22184) {      # F222M, NIC3
		    $score = $score+10.0*3;
		} elsif ($cen == 22183) {      # F222M, NIC3
		    $score = $score+10.0*3;
		} elsif ($cen == 22181) {      # F220M, NIC2
		    $score = $score+10.0*2;
		} elsif ($cen == 20824) {      # F207M, NIC2
		    $score = $score+9.5*2;
		} elsif ($cen == 20355) {      # F204M, NIC2
		    $score = $score+9.0*2;
		} elsif ($cen == 17971) {      # F180M, NIC2
		    $score = $score+5.30*2;
		} elsif ($cen == 17212) {      # F171M, NIC2
		    $score = $score+5.20*2;
		} elsif ($cen == 17067) {      # F170M
		    $score = $score+5.20;
		} elsif ($cen == 16516) {      # F165M,NIC2
		    $score = $score+5.10*2;
		} elsif ($cen == 16489) {      # F165M,NIC1
		    $score = $score+5.10*1;
		} elsif ($cen == 14557) {      # F145M
		    $score = $score+5.00;
		} elsif ($cen == 11026) {      # F110M
		    $score = $score+2.00;
		} elsif ($cen ==  9041) {      # F090M, NIC1
		    $score = $score+1.90;
		} elsif ($cen == 21641) {      # F216N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 21487) {      # F215N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 21488) {      # F215N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 21213) {      # F212N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 19975) {      # F200N
		    $score = $score+2.00;
		} elsif ($cen == 19639) {      # F196N
		    $score = $score+2.00;
		} elsif ($cen == 18986) {      # F190N, NIC1
		    $score = $score+1.00*1;
		} elsif ($cen == 19003) {      # F190N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 19004) {      # F190N, NIC3
		    $score = $score+3.00*3;
		} elsif ($cen == 18748) {      # F187N, NIC1
		    $score = $score+1.00*1;
		} elsif ($cen == 18740) {      # F187N, NIC2
		    $score = $score+2.00*2;
		} elsif ($cen == 18748) {      # F187N, NIC3
		    $score = $score+3.00*3;
		} elsif ($cen == 16460) {      # F164N, NIC2
		    $score = $score+0.50*2;
		} elsif ($cen == 16607) {      # F166N, NIC1
		    $score = $score+0.10*1;
		} elsif ($cen == 16583) {      # F166N, NIC3
		    $score = $score+0.50*3;
		} elsif ($cen == 11284) {      # F113N, NIC3
		    $score = $score+0.20*3;
		} elsif ($cen == 11298) {      # F113N, NIC1
		    $score = $score+0.20*1;
		} elsif ($cen == 10800) {      # F108N, NIC3
		    $score = $score+0.19*3;
		} elsif ($cen == 10799) {      # F108N, NIC3
		    $score = $score+0.19*3;
		} elsif ($cen == 10816) {      # F108N, NIC1
		    $score = $score+0.19*1;
		} elsif ($cen ==  9716) {      # F097N
		    $score = $score+0.01;
		} elsif ($cen ==  9537) {      # F095N
		    $score = $score+0.01;
		} elsif ($cen == 20007) {      # POL0L
		    $score = $score+0.00;
		} elsif ($cen == 10602) {      # POL0S
		    $score = $score+0.00;
		} elsif ($cen ==     0) {      # ??
		    $score = $score+0.00;
		} else {
		    die "GS_SEARCH.PL: Unidentified NICMOS filter $cen!\n";
		}
		$_ = <$remote>;
		# Exposure time in seconds.
		$exp = substr($_,29); $exp =~ s\</TD>\\;
		$exp = sprintf ("%7.2f",$exp);
		$exp = sprintf("%5.0f",$exp);
		$score = $score+$exp/1000.;
		$score = sprintf("%6.2f",$score);
		print "$obj $set $sra $sdec $sep $cen $exp $score\n";
		if ($score > $max_score) {
		    $max_score = $score;
		    $dataset = $set;
		    $ok = 1;
		}
	    }
	}
	close $remote;
	# Download dataset.
	if ($ok) {
	    # Retrieve dataset preview.
	    $remote = IO::Socket::INET->new( Proto     => "tcp",
					     PeerAddr  => $host,
					     PeerPort  => "http(80)"
					     );
	    unless ($remote) {
		die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	    }
	    $remote->autoflush(1);
	    $prompt = "/cgi-bin/hst_preview_search?name=$dataset&imfmt=fits&xfer=log&pc=off&shrink=off&ne=off";
	    print $remote "GET $prompt HTTP/1.0" . $BLANK;
	    $ok = 0;
	    while (<$remote>) {
		if (/SIMPLE  =/) {
		    open (OUT,">$fits") or 
			die "GS_SEARCH.PL: Cannot open output file $fits!\n";
		    $ok = 1;
		}
		if ($ok) {
		    print OUT $_;
		}
	    }
	    close $remote;
	}
	if ($ok) {
	    close (OUT);
	    $dat_nicmos_got = 1;
	} else {
	    print "GS_SEARCH.PL: NICMOS image for $fil is unavailable.\n";
	}
    }
    return;
}

# Routine to access ESO USNO catalog.

sub Get_USNO {
    my ($fil,$ra,$dec) = @_;
    my ($usno) = "images/$fil/$fil.usno";
    if (! -f "$usno" or $fcod) {
	$ra  =~ s/:/+/g;
	$dec =~ s/:/+/g;
	my ($prompt, $theta, $r);
	my ($host) = "archive.eso.org";
	my ($EOL)  = "\015\012";
	my ($BLANK) = $EOL x 2;
	$remote = IO::Socket::INET->new( Proto     => "tcp",
					 PeerAddr  => $host,
					 PeerPort  => "http(80)"
					 );
	unless ($remote) {
	    die "GS_SEARCH.PL: Cannot connect to http daemon on $host!\n";
	}
	$remote->autoflush(1);
	$prompt = "/skycat/servers/usnoa_res?catalogue=usnoa&epoch=2000.0&chart=0&ra=$ra&dec=$dec&object=&radmax=1.5&magbright=0&magfaint=100.0&format=3&sort=d%27&nout=100";
	print $remote "GET $prompt HTTP/1.0" . $BLANK;
	open (OUT,">$usno") or 
	    die "GS_SEARCH.PL: Cannot open output file $usno!\n";
	while (<$remote>) {
	    if (/r_mag b_mag/) {
		$_ = substr($_,3);
		print OUT $_;
		print $_;
		$_ = <$remote>; chomp;
		$_ = substr($_,4);
		while ($_ ne "") {
		    $theta = substr($_,56,8);
		    $r = substr($_,45,5);
		    print "$_\n";
		    if ($theta < 1.5 and $r <= $rlim) {
			print OUT "$_\n";
			print "$_\n";
		    }
		    $_ = <$remote>; chomp;
		}
	    }
	}
	close (OUT);
	$dat_usno_got = 1;
	close $remote;
    }
    return;
}

# Routine to access local version of USNO catalog.

#sub Get_USNO_Local {
#    my ($fil,$ra,$dec) = @_;
#    my ($usno) = "$fil/$fil.usno";
#    Check environment variables have been defined.
#    if ($ENV{'SNSEARCH' } eq "") {die "SNSEARCH not set. Source gs_search.csh!\n";}
#    $sns = $ENV{'SNSEARCH'};
#    if (! -f "$usno" or $fcod) {
#	open (LOC,"$sns/mink.bin/scat -j -p -c ua2 -r -60.0 -n 200 $ra $dec J2000.0 |");
#	open (OUT,">$usno") or 
#	    die "GS_SEARCH.PL: Cannot open output file $usno!\n";
#	while (<LOC>) {
#	    my ($theta) = /^\s*\S+\s*\S+\s*\S+\s*\S+\s*\S+\s*\S+\s*(\S+)/;
#	    my ($r) = substr($_,47,4);
#	    if ($theta < 60.0 and $r <= $rlim) {print OUT $_;}
#	}
#	close (OUT);
#	$dat_usno_got = 1;
#	close (LOC);
#    }
#    return;
#}

# Routine to display downloaded images.

sub Display_Images {
    my ($fil,$ra,$dec,$cod) = @_;
    my ($dis);
    $but_dss2_1_sta = 0;
    $but_dss2_2_sta = 0;
    $but_dss2_3_sta = 0;
    $but_dss2_4_sta = 0;
    $but_dss2_5_sta = 0;
    $but_2mass_1_sta = 0;
    $but_2mass_2_sta = 0;
    $but_2mass_3_sta = 0;
    $but_2mass_4_sta = 0;
    $but_2mass_5_sta = 0;
    $but_wfpc2_1_sta = 0;
    $but_wfpc2_2_sta = 0;
    $but_wfpc2_3_sta = 0;
    $but_wfpc2_4_sta = 0;
    $but_wfpc2_5_sta = 0;
    $but_nicmos_1_sta = 0;
    $but_nicmos_2_sta = 0;
    $but_nicmos_3_sta = 0;
    $but_nicmos_4_sta = 0;
    $but_nicmos_5_sta = 0;
    # Form display device name and open plot file.
    if ($cod == 1) {
	$dis = "/xserve";
	$pltid = pgopen($dis);
	if ($pltid <= 0) {die "GS_SEARCH.PL: Unable to open plot device!";}
    } elsif ($cod == 2) {
	$dis = "images/$fil/$fil.ps/ps";
	$prtid = pgopen($dis);
	if ($prtid <= 0) {die "GS_SEARCH.PL: Unable to open postscript file!";}
    } elsif ($cod == 3) {
	$dis = "images/$fil/$fil.gif/gif";
	$gifid = pgopen($dis);
	if ($gifid <= 0) {die "GS_SEARCH.PL: Unable to open gif file!";}
    } else {
	print "GS_SEARCH.PL: Invalid display code!\n";
	return;
    }
    # Define colors.
    if ($cod == 1) {
	pgscr(0,0,0.7,1);
	pgscr(1,0,0,0);
    } elsif ($cod == 2) {
	pgscr(10,1,1,1);
    } elsif ($cod == 3) {
	pgscr(0,0,0.7,1);
	pgscr(1,0,0,0);
    }
    Color_Table($col_tab,$col_con,$col_bri);
    # Plot title.
    Plt_Title($obj,$ra,$dec);
    # Plot DSS2 red image.
    Plt_DSS2_R($fil,$ra,$dec);
    # Plot 2MASS K image.
    Plt_2MASS_K($fil,$ra,$dec);
    # Plot WFPC2 image.
    Plt_WFPC2($fil,$ra,$dec);
    # Plot NICMOS image.
    Plt_NICMOS($fil,$ra,$dec);

    # Interactively adjust plot parameters.

    if ($cod == 1) {
	Adjust_Plt($fil);
    }

    pgclos;
    return;
}

# Routine to write object data file.

sub Write_Data {
    my ($fil) = @_;
    my $dat = "images/$fil/$fil.dat";
    open (DAT,">$dat") or 
	die "GS_SEARCH.PL: Cannot open object data file $dat.\n";
    print DAT "$obj\n";
    print DAT "$ra\n";
    print DAT "$dec\n";
    print DAT "$col_tab\n";
    print DAT "$col_bri\n";
    print DAT "$col_con\n";
    print DAT "$dat_dss2_got\n";
    print DAT "$ima_dss2_x_off\n";
    print DAT "$ima_dss2_y_off\n";
    print DAT "$ima_dss2_x_zoom\n";
    print DAT "$ima_dss2_y_zoom\n";
    print DAT "$ima_dss2_min\n";
    print DAT "$ima_dss2_max\n";
    print DAT "$dat_2mass_got\n";
    print DAT "$ima_2mass_x_off\n";
    print DAT "$ima_2mass_y_off\n";
    print DAT "$ima_2mass_x_zoom\n";
    print DAT "$ima_2mass_y_zoom\n";
    print DAT "$ima_2mass_min\n";
    print DAT "$ima_2mass_max\n";
    print DAT "$dat_wfpc2_got\n";
    print DAT "$ima_wfpc2_x_off\n";
    print DAT "$ima_wfpc2_y_off\n";
    print DAT "$ima_wfpc2_x_zoom\n";
    print DAT "$ima_wfpc2_y_zoom\n";
    print DAT "$ima_wfpc2_min\n";
    print DAT "$ima_wfpc2_max\n";
    print DAT "$dat_nicmos_got\n";
    print DAT "$ima_nicmos_x_off\n";
    print DAT "$ima_nicmos_y_off\n";
    print DAT "$ima_nicmos_x_zoom\n";
    print DAT "$ima_nicmos_y_zoom\n";
    print DAT "$ima_nicmos_min\n";
    print DAT "$ima_nicmos_max\n";
    print DAT "$dat_usno_got\n";
    print DAT "$dat_aowfs_got\n";
    print DAT "$dat_aowfs_ra\n";
    print DAT "$dat_aowfs_dec\n";
    print DAT "$dat_oiwfs_got\n";
    print DAT "$dat_oiwfs_ra\n";
    print DAT "$dat_oiwfs_dec\n";
    print DAT "$ima_dss2_grid\n";
    print DAT "$ima_dss2_grot\n";
    print DAT "$ima_2mass_grid\n";
    print DAT "$ima_2mass_grot\n";
    print DAT "$ima_wfpc2_grid\n";
    print DAT "$ima_wfpc2_grot\n";
    print DAT "$ima_nicmos_grid\n";
    print DAT "$ima_nicmos_grot\n";
    close (DAT);
    return;
}

# Routine to read object data file.

sub Read_Data {
    my ($fil) = @_;
    my $dat = "images/$fil/$fil.dat";
    open (DAT,"<$dat") or return 0;
    $obj               = <DAT>; chomp $obj; $obj = sprintf("%-15.15s",$obj);
    $ra                = <DAT>; chomp $ra;
    $dec               = <DAT>; chomp $dec;
    print "$obj $ra $dec\n";
    $col_tab           = <DAT>; chomp $col_tab;
    $col_bri           = <DAT>; chomp $col_bri;
    $col_con           = <DAT>; chomp $col_con;
    $dat_dss2_got      = <DAT>; chomp $dat_dss2_got;
    $ima_dss2_x_off    = <DAT>; chomp $ima_dss2_x_off;
    $ima_dss2_y_off    = <DAT>; chomp $ima_dss2_y_off;
    $ima_dss2_x_zoom   = <DAT>; chomp $ima_dss2_x_zoom;
    $ima_dss2_y_zoom   = <DAT>; chomp $ima_dss2_y_zoom;
    $ima_dss2_min      = <DAT>; chomp $ima_dss2_min;
    $ima_dss2_max      = <DAT>; chomp $ima_dss2_max;
    $dat_2mass_got     = <DAT>; chomp $dat_2mass_got;
    $ima_2mass_x_off   = <DAT>; chomp $ima_2mass_x_off;
    $ima_2mass_y_off   = <DAT>; chomp $ima_2mass_y_off;
    $ima_2mass_x_zoom  = <DAT>; chomp $ima_2mass_x_zoom;
    $ima_2mass_y_zoom  = <DAT>; chomp $ima_2mass_y_zoom;
    $ima_2mass_min     = <DAT>; chomp $ima_2mass_min;
    $ima_2mass_max     = <DAT>; chomp $ima_2mass_max;
    $dat_wfpc2_got     = <DAT>; chomp $dat_wfpc2_got;
    $ima_wfpc2_x_off   = <DAT>; chomp $ima_wfpc2_x_off;
    $ima_wfpc2_y_off   = <DAT>; chomp $ima_wfpc2_y_off;
    $ima_wfpc2_x_zoom  = <DAT>; chomp $ima_wfpc2_x_zoom;
    $ima_wfpc2_y_zoom  = <DAT>; chomp $ima_wfpc2_y_zoom;
    $ima_wfpc2_min     = <DAT>; chomp $ima_wfpc2_min;
    $ima_wfpc2_max     = <DAT>; chomp $ima_wfpc2_max;
    $dat_nicmos_got    = <DAT>; chomp $dat_nicmos_got;
    $ima_nicmos_x_off  = <DAT>; chomp $ima_nicmos_x_off;
    $ima_nicmos_y_off  = <DAT>; chomp $ima_nicmos_y_off;
    $ima_nicmos_x_zoom = <DAT>; chomp $ima_nicmos_x_zoom;
    $ima_nicmos_y_zoom = <DAT>; chomp $ima_nicmos_y_zoom;
    $ima_nicmos_min    = <DAT>; chomp $ima_nicmos_min;
    $ima_nicmos_max    = <DAT>; chomp $ima_nicmos_max;
    $dat_usno_got      = <DAT>; chomp $dat_usno_got;
    # The remaining entries were added recently and may not be 
    # present for all objects.
    $dat_aowfs_got     = <DAT>;
    if (defined($dat_aowfs_got)){
	chomp $dat_aowfs_got;
    } else {
	$dat_aowfs_got = 0;
    }
    $dat_aowfs_ra      = <DAT>;
    if (defined($dat_aowfs_ra)){
	chomp $dat_aowfs_ra;
    } else {
	$dat_aowfs_ra = 0;
    }
    $dat_aowfs_dec     = <DAT>;
    if (defined($dat_aowfs_dec)){
	chomp $dat_aowfs_dec;
    } else {
	$dat_aowfs_dec = 0;
    }
    $dat_oiwfs_got     = <DAT>;
    if (defined($dat_oiwfs_got)){
	chomp $dat_oiwfs_got;
    } else {
	$dat_oiwfs_got = 0;
    }
    $dat_oiwfs_ra      = <DAT>;
    if (defined($dat_oiwfs_ra)){
	chomp $dat_oiwfs_ra;
    } else {
	$dat_oiwfs_ra = 0;
    }
    $dat_oiwfs_dec     = <DAT>;
    if (defined($dat_oiwfs_dec)){
	chomp $dat_oiwfs_dec;
    } else {
	$dat_oiwfs_dec = 0;
    }
    $ima_dss2_grid     = <DAT>;
    if (defined($ima_dss2_grid)){
	chomp $ima_dss2_grid;
    } else {
	$ima_dss2_grid = 0;
    }
    $ima_dss2_grot     = <DAT>;
    if (defined($ima_dss2_grot)){
	chomp $ima_dss2_grot;
    } else {
	$ima_dss2_grot = 0;
    }
    $ima_2mass_grid    = <DAT>;
    if (defined($ima_2mass_grid)){
	chomp $ima_2mass_grid;
    } else {
	$ima_2mass_grid = 0;
    }
    $ima_2mass_grot    = <DAT>;
    if (defined($ima_2mass_grot)){
	chomp $ima_2mass_grot;
    } else {
	$ima_2mass_grot = 0;
    }
    $ima_wfpc2_grid    = <DAT>;
    if (defined($ima_wfpc2_grid)){
	chomp $ima_wfpc2_grid;
    } else {
	$ima_wfpc2_grid = 0;
    }
    $ima_wfpc2_grot    = <DAT>;
    if (defined($ima_wfpc2_grot)){
	chomp $ima_wfpc2_grot;
    } else {
	$ima_wfpc2_grot = 0;
    }
    $ima_nicmos_grid   = <DAT>;
    if (defined($ima_nicmos_grid)){
	chomp $ima_nicmos_grid;
    } else {
	$ima_nicmos_grid = 0;
    }
    $ima_nicmos_grot   = <DAT>;
    if (defined($ima_nicmos_grot)){
	chomp $ima_nicmos_grot;
    } else {
	$ima_nicmos_grot = 0;
    }
    close (DAT);
    return 1;
}

# Routine to plot title.

sub Plt_Title {
    my ($obj,$ra,$dec) = @_;
    pgsvp(0,0.5,0.9,1);
    pgswin(0,1,0,1);
    pgsci(0);
    pgrect(0,1,0,1);
    pgsci(1);
    pgsci(1);                  # Set color index (default).
    pgslw(2);                  # Set line width (1=default).
    pgscf(2);                  # Set character font (1=default; 2=roman).
    pgsch(2);                  # Set character height.
    pgptxt(0.0,0.65,0.0,0.0,$obj);
    pgsch(1.5);
    pgptxt(0.0,0.2,0.0,0.0,"$ra $dec J2000");
    pgslw(1);
    pgsch(1);
    # Draw "Color" button.
    $but_title_1_x_vst = 0.50;
    $but_title_1_x_vsp = 0.61;
    $but_title_1_y_vst = 0.94;
    $but_title_1_y_vsp = 0.99;
    $but_title_1_lab = "Color";
    Plt_Button($but_title_1_x_vst,
               $but_title_1_x_vsp,
               $but_title_1_y_vst,
	       $but_title_1_y_vsp,
	       $but_title_1_lab,
	       $but_title_1_sta);
    # Draw "Print" button.
    $but_title_2_x_vst = 0.63;
    $but_title_2_x_vsp = 0.74;
    $but_title_2_y_vst = 0.94;
    $but_title_2_y_vsp = 0.99;
    $but_title_2_lab = "Print";
    Plt_Button($but_title_2_x_vst,
               $but_title_2_x_vsp,
               $but_title_2_y_vst,
	       $but_title_2_y_vsp,
	       $but_title_2_lab,
	       $but_title_2_sta);
    # Draw "Next" button.
    $but_title_3_x_vst = 0.76;
    $but_title_3_x_vsp = 0.87;
    $but_title_3_y_vst = 0.94;
    $but_title_3_y_vsp = 0.99;
    $but_title_3_lab = "Next";
    Plt_Button($but_title_3_x_vst,
               $but_title_3_x_vsp,
               $but_title_3_y_vst,
	       $but_title_3_y_vsp,
	       $but_title_3_lab,
	       $but_title_3_sta);
    # Draw "Quit" button.
    $but_title_4_x_vst = 0.89;
    $but_title_4_x_vsp = 1.00;
    $but_title_4_y_vst = 0.94;
    $but_title_4_y_vsp = 0.99;
    $but_title_4_lab = "Quit";
    Plt_Button($but_title_4_x_vst,
               $but_title_4_x_vsp,
               $but_title_4_y_vst,
	       $but_title_4_y_vsp,
	       $but_title_4_lab,
	       $but_title_4_sta);
    return;
}

# Routine to plot DSS2 red image.

sub Plt_DSS2_R {
    my ($fil,$ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    my ($xscale, $yscale, $coord, $size);
    my ($tr) = [0,1,0,0,0,1];
    my ($fits) = "images/$fil/$fil"."_dss2_r.fits";
    my ($usno) = "images/$fil/$fil.usno";
    $ima_dss2_x_vst = 0.01;
    $ima_dss2_x_vsp = 0.35;
    $ima_dss2_y_vst = 0.47;
    $ima_dss2_y_vsp = 0.85;
    $but_dss2_1_x_vst = 0.36;
    $but_dss2_1_x_vsp = 0.47;
    $but_dss2_1_y_vst = 0.80;
    $but_dss2_1_y_vsp = 0.85;
    $but_dss2_1_lab = "Zoom";
    $but_dss2_2_x_vst = 0.36;
    $but_dss2_2_x_vsp = 0.47;
    $but_dss2_2_y_vst = 0.72;
    $but_dss2_2_y_vsp = 0.77;
    $but_dss2_2_lab = "Unzoom";
    $but_dss2_3_x_vst = 0.36;
    $but_dss2_3_x_vsp = 0.47;
    $but_dss2_3_y_vst = 0.64;
    $but_dss2_3_y_vsp = 0.69;
    $but_dss2_3_lab = "Center";
    $but_dss2_4_x_vst = 0.36;
    $but_dss2_4_x_vsp = 0.47;
    $but_dss2_4_y_vst = 0.56;
    $but_dss2_4_y_vsp = 0.61;
    $but_dss2_4_lab = "Range";
    $but_dss2_5_x_vst = 0.36;
    $but_dss2_5_x_vsp = 0.47;
    $but_dss2_5_y_vst = 0.48;
    $but_dss2_5_y_vsp = 0.53;
    $but_dss2_5_lab = "Reset";
    pgsci(1);                  # Set color index (default).
    pgslw(1);                  # Set line width (1=default).
    pgscf(2);                  # Set character font (1=default; 2=roman).
    pgsch(1.0);                # Set character height.
    # Draw bounding box.
    pgsvp(0.00,0.50,0.45,0.90);
    pgswin(0,1,0,1);
    pgsci(0);
    pgrect(0,1,0,1);
    pgsci(1);
    pgbox('BC',0.0,0,'BC',0.0,0);
    pgptxt(0.5,0.92,0.0,0.5,"DSS-2 Red");
    # Read FITS file.
    if (! $dat_dss2_read) {
	($dat_dss2_got,$dat_dss2_data,$dat_dss2_nx,$dat_dss2_ny,
	 $dat_dss2_hdr,$dat_dss2_min,$dat_dss2_max) = Read_FITS($fits);
	if ($ima_dss2_min > $ima_dss2_max) {
	    $ima_dss2_min = $dat_dss2_min;
	    $ima_dss2_max = $dat_dss2_max;
	}
	$dat_dss2_read = 1;  # .true.
    }
    if (! $dat_dss2_got) {
	pgptxt(0.5,0.5,0.0,0.5,"No DSS-2 Red image available.");
	return;
    }
    # Plot image.
    pgsch(0.5);
    pgsvp($ima_dss2_x_vst,$ima_dss2_x_vsp,
	  $ima_dss2_y_vst,$ima_dss2_y_vsp);
    $rh = substr($ra, 0,2);
    $rm = substr($ra, 3,2);
    $rs = substr($ra, 6,5);
    $dc = substr($dec,0,1);
    $dd = substr($dec,1,2);
    $dm = substr($dec,4,2);
    $ds = substr($dec,7,4);
    ($ima_dss2_x_cen,$ima_dss2_y_cen) = 
	RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$dat_dss2_hdr);
    # Image scale in arcsec/pixel.
#    $xscale = $dat_dss2_hdr->{'PLTSCALE'}*$dat_dss2_hdr->{'XPIXELSZ'}/1000;
#    $yscale = $dat_dss2_hdr->{'PLTSCALE'}*$dat_dss2_hdr->{'YPIXELSZ'}/1000;
    $xscale = abs($dat_dss2_hdr->{'CDELT1'}*3600);
    $yscale = abs($dat_dss2_hdr->{'CDELT2'}*3600);
    $ima_dss2_x_wst = $ima_dss2_x_cen+$ima_dss2_x_off
	-90/$ima_dss2_x_zoom/$xscale;
    $ima_dss2_x_wsp = $ima_dss2_x_cen+$ima_dss2_x_off
	+90/$ima_dss2_x_zoom/$xscale;
    $ima_dss2_y_wst = $ima_dss2_y_cen+$ima_dss2_y_off
	-90/$ima_dss2_y_zoom/$yscale;
    $ima_dss2_y_wsp = $ima_dss2_y_cen+$ima_dss2_y_off
	+90/$ima_dss2_y_zoom/$yscale;
    pgwnad($ima_dss2_x_wst,$ima_dss2_x_wsp,
	   $ima_dss2_y_wst,$ima_dss2_y_wsp);
    pgqvp(0,$ima_dss2_x_vst,$ima_dss2_x_vsp,
	    $ima_dss2_y_vst,$ima_dss2_y_vsp);
    pgsci(0);
    pgrect($ima_dss2_x_wst,$ima_dss2_x_wsp,
	   $ima_dss2_y_wst,$ima_dss2_y_wsp);
    pgsci(1);
    pgimag($dat_dss2_data,$dat_dss2_nx,$dat_dss2_ny,1,$dat_dss2_nx,
	   1,$dat_dss2_ny,$ima_dss2_max,$ima_dss2_min,$tr);
    pgbox('BCNST',0.0,0,'BCNST',0.0,0);
    # Draw 3"x3" NIFS field.
    pgsci(3);
    pgsfs(2);
    pgrect($ima_dss2_x_cen-1.5/$xscale,$ima_dss2_x_cen+1.5/$xscale,
	   $ima_dss2_y_cen-1.5/$yscale,$ima_dss2_y_cen+1.5/$yscale);
    pgsfs(1);
    # Draw NIFS FOV grid.
    if ($ima_dss2_grid) {
	pgsci(3);
	pgsfs(2);
	foreach $i (-60..61) {
	    $x = $ima_dss2_x_cen-1.5/$xscale+$i*3.0/$xscale;
	    if ($x > 0 and $x < $dat_dss2_nx) {
		pgmove($x,0);
		pgdraw($x,$dat_dss2_ny);
	    }
	}
	foreach $i (-60..61) {
	    $y = $ima_dss2_y_cen-1.5/$yscale+$i*3.0/$yscale;
	    if ($y > 0 and $y < $dat_dss2_ny) {
		pgmove(0,$y);
		pgdraw($dat_dss2_nx,$y);
	    }
	}
	pgsfs(1);
    }
    # Draw 60" radius ALTAIR field.
    pgsci(2);
    Plt_Circle($ima_dss2_x_cen,$ima_dss2_y_cen,60.0/$xscale);
    # Draw 90" radius OIWFS field.
    pgsci(2);
    Plt_Circle($ima_dss2_x_cen,$ima_dss2_y_cen,90.0/$xscale);
    # Draw 12.7" radius pickoff mirror field.
    pgsci(2);
    Plt_Circle($ima_dss2_x_cen,$ima_dss2_y_cen,12.7/$xscale);
    $x = $ima_dss2_x_cen+12.7/$xscale;
    $y = $ima_dss2_y_cen;
    pgmove($x,$y);
    $y = $ima_dss2_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    $x = $ima_dss2_x_cen-12.7/$xscale;
    $y = $ima_dss2_y_cen;
    pgmove($x,$y);
    $y = $ima_dss2_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    # Draw 20" radius NGS field.
    pgsci(4);
    Plt_Circle($ima_dss2_x_cen,$ima_dss2_y_cen,20.0/$xscale);
    # Draw 30" radius LGS field.
    pgsci(4);
    Plt_Circle($ima_dss2_x_cen,$ima_dss2_y_cen,30.0/$xscale);
    pgsci(1);
    # Overlay USNO stars.
    if ($dat_usno_got) {
	open (IN,"$usno") or
	    die "GS_SEARCH.PL: Cannot open input file $usno!\n";
	$size = 5/$xscale;
	$_ = <IN>;
	while (<IN>) {
	    $coord = substr($_,21,23);
	    Mark_USNO($coord,$size,$dat_dss2_hdr);
	}
	close (IN);
    }
    # Overlay AOWFS guide star.
    if ($dat_aowfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_aowfs_ra $dat_aowfs_dec";
	Mark_AOWFS($coord,$size,$dat_dss2_hdr);
    }
    # Overlay OIWFS guide star.
    if ($dat_oiwfs_got) {
	$size = 3.0/$xscale;
	$coord = "$dat_oiwfs_ra $dat_oiwfs_dec";
	Mark_OIWFS($coord,$size,$dat_dss2_hdr);
    }
    # Draw "Zoom" button.
    Plt_Button($but_dss2_1_x_vst,
               $but_dss2_1_x_vsp,
               $but_dss2_1_y_vst,
	       $but_dss2_1_y_vsp,
	       $but_dss2_1_lab,
	       $but_dss2_1_sta);
    # Draw "Unzoom" button.
    Plt_Button($but_dss2_2_x_vst,
               $but_dss2_2_x_vsp,
               $but_dss2_2_y_vst,
	       $but_dss2_2_y_vsp,
	       $but_dss2_2_lab,
	       $but_dss2_2_sta);
    # Draw "Center" button.
    Plt_Button($but_dss2_3_x_vst,
               $but_dss2_3_x_vsp,
               $but_dss2_3_y_vst,
	       $but_dss2_3_y_vsp,
	       $but_dss2_3_lab,
	       $but_dss2_3_sta);
    # Draw "Range" button.
    Plt_Button($but_dss2_4_x_vst,
               $but_dss2_4_x_vsp,
               $but_dss2_4_y_vst,
	       $but_dss2_4_y_vsp,
	       $but_dss2_4_lab,
	       $but_dss2_4_sta);
    # Draw "Reset" button.
    Plt_Button($but_dss2_5_x_vst,
               $but_dss2_5_x_vsp,
               $but_dss2_5_y_vst,
	       $but_dss2_5_y_vsp,
	       $but_dss2_5_lab,
	       $but_dss2_5_sta);
    pgsvp(0,1,0,1);
    pgswin(0,1,0,1);
    return;
}

# Routine to plot 2MASS K image.

sub Plt_2MASS_K {
    my ($fil,$ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    my ($xscale, $yscale, $coord, $size);
    my ($tr) = [0,1,0,0,0,1];
    my ($fits) = "images/$fil/$fil"."_2mass_k.fits";
    my ($usno) = "images/$fil/$fil.usno";
    $ima_2mass_x_vst = 0.51;
    $ima_2mass_x_vsp = 0.85;
    $ima_2mass_y_vst = 0.47;
    $ima_2mass_y_vsp = 0.85;
    $but_2mass_1_x_vst = 0.86;
    $but_2mass_1_x_vsp = 0.97;
    $but_2mass_1_y_vst = 0.80;
    $but_2mass_1_y_vsp = 0.85;
    $but_2mass_1_lab = "Zoom";
    $but_2mass_2_x_vst = 0.86;
    $but_2mass_2_x_vsp = 0.97;
    $but_2mass_2_y_vst = 0.72;
    $but_2mass_2_y_vsp = 0.77;
    $but_2mass_2_lab = "Unzoom";
    $but_2mass_3_x_vst = 0.86;
    $but_2mass_3_x_vsp = 0.97;
    $but_2mass_3_y_vst = 0.64;
    $but_2mass_3_y_vsp = 0.69;
    $but_2mass_3_lab = "Center";
    $but_2mass_4_x_vst = 0.86;
    $but_2mass_4_x_vsp = 0.97;
    $but_2mass_4_y_vst = 0.56;
    $but_2mass_4_y_vsp = 0.61;
    $but_2mass_4_lab = "Range";
    $but_2mass_5_x_vst = 0.86;
    $but_2mass_5_x_vsp = 0.97;
    $but_2mass_5_y_vst = 0.48;
    $but_2mass_5_y_vsp = 0.53;
    $but_2mass_5_lab = "Reset";
    pgsci(1);                  # Set color index (default).
    pgslw(1);                  # Set line width (1=default).
    pgscf(2);                  # Set character font (1=default; 2=roman).
    pgsch(1.0);                # Set character height.
    # Draw bounding box.
    pgsvp(0.50,1.00,0.45,0.90);
    pgswin(0,1,0,1);
    pgsci(0);
    pgrect(0,1,0,1);
    pgsci(1);
    pgbox('BC',0.0,0,'BC',0.0,0);
    pgptxt(0.5,0.92,0.0,0.5,"2MASS K");
    # Read FITS file.
    if (! $dat_2mass_read) {
	($dat_2mass_got,$dat_2mass_data,$dat_2mass_nx,$dat_2mass_ny,
	 $dat_2mass_hdr,$dat_2mass_min,$dat_2mass_max) = Read_FITS($fits);
	if ($ima_2mass_min > $ima_2mass_max) {
	    $ima_2mass_min = $dat_2mass_min;
	    $ima_2mass_max = $dat_2mass_max;
	}
	$dat_2mass_read = 1;  # .true.
    }
    if (! $dat_2mass_got) {
	pgptxt(0.5,0.5,0.0,0.5,"No 2MASS K image available.");
	$ima_2mass_min = 0;
	$ima_2mass_max = 0;
	return;
    }
    # Plot image.
    pgsch(0.5);
    pgsvp($ima_2mass_x_vst,$ima_2mass_x_vsp,
	  $ima_2mass_y_vst,$ima_2mass_y_vsp);
    $rh = substr($ra, 0,2);
    $rm = substr($ra, 3,2);
    $rs = substr($ra, 6,5);
    $dc = substr($dec,0,1);
    $dd = substr($dec,1,2);
    $dm = substr($dec,4,2);
    $ds = substr($dec,7,4);
    ($ima_2mass_x_cen,$ima_2mass_y_cen) = 
	RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$dat_2mass_hdr);
    # Image scale in arcsec/pixel.
    $xscale = abs($dat_2mass_hdr->{'CDELT1'}*3600);
    $yscale = abs($dat_2mass_hdr->{'CDELT2'}*3600);
    $ima_2mass_x_wst = $ima_2mass_x_cen+$ima_2mass_x_off
	-90/$ima_2mass_x_zoom/$xscale;
    $ima_2mass_x_wsp = $ima_2mass_x_cen+$ima_2mass_x_off
	+90/$ima_2mass_x_zoom/$xscale;
    $ima_2mass_y_wst = $ima_2mass_y_cen+$ima_2mass_y_off
	-90/$ima_2mass_y_zoom/$yscale;
    $ima_2mass_y_wsp = $ima_2mass_y_cen+$ima_2mass_y_off
	+90/$ima_2mass_y_zoom/$yscale;
    pgwnad($ima_2mass_x_wst,$ima_2mass_x_wsp,
	   $ima_2mass_y_wst,$ima_2mass_y_wsp);
    pgqvp(0,$ima_2mass_x_vst,$ima_2mass_x_vsp,
	    $ima_2mass_y_vst,$ima_2mass_y_vsp);
    pgsci(0);
    pgrect($ima_2mass_x_wst,$ima_2mass_x_wsp,
	   $ima_2mass_y_wst,$ima_2mass_y_wsp);
    pgsci(1);
    pgimag($dat_2mass_data,$dat_2mass_nx,$dat_2mass_ny,1,$dat_2mass_nx,
	   1,$dat_2mass_ny,$ima_2mass_max,$ima_2mass_min,$tr);
    pgbox('BCNST',0.0,0,'BCNST',0.0,0);
    # Draw 3"x3" NIFS field.
    pgsci(3);
    pgsfs(2);
    pgrect($ima_2mass_x_cen-1.5/$xscale,$ima_2mass_x_cen+1.5/$xscale,
	   $ima_2mass_y_cen-1.5/$yscale,$ima_2mass_y_cen+1.5/$yscale);
    pgsfs(1);
    # Draw NIFS FOV grid.
    if ($ima_2mass_grid) {
	pgsci(3);
	pgsfs(2);
	foreach $i (-60..61) {
	    $x = $ima_2mass_x_cen-1.5/$xscale+$i*3.0/$xscale;
	    if ($x > 0 and $x < $dat_2mass_nx) {
		pgmove($x,0);
		pgdraw($x,$dat_2mass_ny);
	    }
	}
	foreach $i (-60..61) {
	    $y = $ima_2mass_y_cen-1.5/$yscale+$i*3.0/$yscale;
	    if ($y > 0 and $y < $dat_2mass_ny) {
		pgmove(0,$y);
		pgdraw($dat_2mass_nx,$y);
	    }
	}
	pgsfs(1);
    }
    # Draw 60" radius ALTAIR field.
    pgsci(2);
    Plt_Circle($ima_2mass_x_cen,$ima_2mass_y_cen,60.0/$xscale);
    # Draw 90" radius OIWFS field.
    pgsci(2);
    Plt_Circle($ima_2mass_x_cen,$ima_2mass_y_cen,90.0/$xscale);
    # Draw 12.7" radius pickoff mirror field.
    pgsci(2);
    Plt_Circle($ima_2mass_x_cen,$ima_2mass_y_cen,12.7/$xscale);
    $x = $ima_2mass_x_cen+12.7/$xscale;
    $y = $ima_2mass_y_cen;
    pgmove($x,$y);
    $y = $ima_2mass_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    $x = $ima_2mass_x_cen-12.7/$xscale;
    $y = $ima_2mass_y_cen;
    pgmove($x,$y);
    $y = $ima_2mass_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    # Draw 20" radius NGS field.
    pgsci(4);
    Plt_Circle($ima_2mass_x_cen,$ima_2mass_y_cen,20.0/$xscale);
    # Draw 30" radius LGS field.
    pgsci(4);
    Plt_Circle($ima_2mass_x_cen,$ima_2mass_y_cen,30.0/$xscale);
    pgsci(1);
    # Overlay USNO stars.
    if ($dat_usno_got) {
	open (IN,"$usno") or
	    die "GS_SEARCH.PL: Cannot open input file $usno!\n";
	$size = 5/$xscale;
	$_ = <IN>;
	while (<IN>) {
	    $coord = substr($_,21,23);
	    Mark_USNO($coord,$size,$dat_2mass_hdr);
	}
	close (IN);
    }
    # Overlay AOWFS guide star.
    if ($dat_aowfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_aowfs_ra $dat_aowfs_dec";
	Mark_AOWFS($coord,$size,$dat_2mass_hdr);
    }
    # Overlay OIWFS guide star.
    if ($dat_oiwfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_oiwfs_ra $dat_oiwfs_dec";
	Mark_OIWFS($coord,$size,$dat_2mass_hdr);
    }
    # Draw "Zoom" button.
    Plt_Button($but_2mass_1_x_vst,
               $but_2mass_1_x_vsp,
               $but_2mass_1_y_vst,
	       $but_2mass_1_y_vsp,
	       $but_2mass_1_lab,
	       $but_2mass_1_sta);
    # Draw "Unzoom" button.
    Plt_Button($but_2mass_2_x_vst,
               $but_2mass_2_x_vsp,
               $but_2mass_2_y_vst,
	       $but_2mass_2_y_vsp,
	       $but_2mass_2_lab,
	       $but_2mass_2_sta);
    # Draw "Center" button.
    Plt_Button($but_2mass_3_x_vst,
               $but_2mass_3_x_vsp,
               $but_2mass_3_y_vst,
	       $but_2mass_3_y_vsp,
	       $but_2mass_3_lab,
	       $but_2mass_3_sta);
    # Draw "Range" button.
    Plt_Button($but_2mass_4_x_vst,
               $but_2mass_4_x_vsp,
               $but_2mass_4_y_vst,
	       $but_2mass_4_y_vsp,
	       $but_2mass_4_lab,
	       $but_2mass_4_sta);
    # Draw "Reset" button.
    Plt_Button($but_2mass_5_x_vst,
               $but_2mass_5_x_vsp,
               $but_2mass_5_y_vst,
	       $but_2mass_5_y_vsp,
	       $but_2mass_5_lab,
	       $but_2mass_5_sta);
    pgsvp(0,1,0,1);
    pgswin(0,1,0,1);
    return;
}

# Routine to plot a WFPC2 image.

sub Plt_WFPC2 {
    my ($fil,$ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    my ($xscale, $yscale, $coord, $size, $crota2, $dec_rad, $title);
    my ($tr) = [0,1,0,0,0,1];
    my ($fits) = "images/$fil/$fil"."_wfpc2.fits";
    my ($usno) = "images/$fil/$fil.usno";
    my ($pi) = 3.14159265359;
    $ima_wfpc2_x_vst = 0.01;
    $ima_wfpc2_x_vsp = 0.35;
    $ima_wfpc2_y_vst = 0.02;
    $ima_wfpc2_y_vsp = 0.40;
    $but_wfpc2_1_x_vst = 0.36;
    $but_wfpc2_1_x_vsp = 0.47;
    $but_wfpc2_1_y_vst = 0.35;
    $but_wfpc2_1_y_vsp = 0.40;
    $but_wfpc2_1_lab = "Zoom";
    $but_wfpc2_2_x_vst = 0.36;
    $but_wfpc2_2_x_vsp = 0.47;
    $but_wfpc2_2_y_vst = 0.27;
    $but_wfpc2_2_y_vsp = 0.32;
    $but_wfpc2_2_lab = "Unzoom";
    $but_wfpc2_3_x_vst = 0.36;
    $but_wfpc2_3_x_vsp = 0.47;
    $but_wfpc2_3_y_vst = 0.19;
    $but_wfpc2_3_y_vsp = 0.24;
    $but_wfpc2_3_lab = "Center";
    $but_wfpc2_4_x_vst = 0.36;
    $but_wfpc2_4_x_vsp = 0.47;
    $but_wfpc2_4_y_vst = 0.11;
    $but_wfpc2_4_y_vsp = 0.16;
    $but_wfpc2_4_lab = "Range";
    $but_wfpc2_5_x_vst = 0.36;
    $but_wfpc2_5_x_vsp = 0.47;
    $but_wfpc2_5_y_vst = 0.03;
    $but_wfpc2_5_y_vsp = 0.08;
    $but_wfpc2_5_lab = "Reset";
    pgsci(1);                  # Set color index (default).
    pgslw(1);                  # Set line width (1=default).
    pgscf(2);                  # Set character font (1=default; 2=roman).
    pgsch(1.0);                # Set character height.
    # Draw bounding box.
    pgsvp(0.00,0.50,0.00,0.45);
    pgswin(0,1,0,1);
    pgsci(0);
    pgrect(0,1,0,1);
    pgsci(1);
    pgbox('BC',0.0,0,'BC',0.0,0);
    # Read FITS file.
    if (! $dat_wfpc2_read) {
	($dat_wfpc2_got,$dat_wfpc2_data,$dat_wfpc2_nx,$dat_wfpc2_ny,
	 $dat_wfpc2_hdr,$dat_wfpc2_min,$dat_wfpc2_max) = Read_FITS($fits);
	if ($ima_wfpc2_min > $ima_wfpc2_max) {
	    $ima_wfpc2_min = $dat_wfpc2_min;
	    $ima_wfpc2_max = $dat_wfpc2_max;
	}
	$dat_wfpc2_read = 1;  # .true.
    }
    if (! $dat_wfpc2_got) {
	pgptxt(0.5,0.92,0.0,0.5,"WFPC2");
	pgptxt(0.5,0.5,0.0,0.5,"No WFPC2 image available.");
	$ima_wfpc2_min = 0;
	$ima_wfpc2_max = 0;
	return;
    } else {
	$title = $dat_wfpc2_hdr->{'FILTNAM1'};
	$title = substr($title,1,length($title)-2); $title =~ s/\s{1}//g;
	pgptxt(0.5,0.92,0.0,0.5,"WFPC2 $title");
    }
    # Plot image.
    pgsch(0.5);
    pgsvp($ima_wfpc2_x_vst,$ima_wfpc2_x_vsp,
	  $ima_wfpc2_y_vst,$ima_wfpc2_y_vsp);
    $rh = substr($ra, 0,2);
    $rm = substr($ra, 3,2);
    $rs = substr($ra, 6,5);
    $dc = substr($dec,0,1);
    $dd = substr($dec,1,2);
    $dm = substr($dec,4,2);
    $ds = substr($dec,7,4);
    $dec_rad = ($dd+$dm/60+$ds/3600)*$pi/180;
    if ($dc eq "-") {$dec_rad *= -1;}
    ($ima_wfpc2_x_cen,$ima_wfpc2_y_cen) = 
	RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$dat_wfpc2_hdr);
    # Image scale in arcsec/pixel.
    $crota2 = atan2($dat_wfpc2_hdr->{'CD2_1'},$dat_wfpc2_hdr->{'CD1_1'});
    $xscale = abs($dat_wfpc2_hdr->{'CD1_1'}/cos($crota2)*3600);
    $yscale = abs($dat_wfpc2_hdr->{'CD2_2'}/cos($crota2)*3600);
    $ima_wfpc2_x_wst = $ima_wfpc2_x_cen+$ima_wfpc2_x_off
	-90/$ima_wfpc2_x_zoom/$xscale;
    $ima_wfpc2_x_wsp = $ima_wfpc2_x_cen+$ima_wfpc2_x_off
	+90/$ima_wfpc2_x_zoom/$xscale;
    $ima_wfpc2_y_wst = $ima_wfpc2_y_cen+$ima_wfpc2_y_off
	-90/$ima_wfpc2_y_zoom/$yscale;
    $ima_wfpc2_y_wsp = $ima_wfpc2_y_cen+$ima_wfpc2_y_off
	+90/$ima_wfpc2_y_zoom/$yscale;
    pgwnad($ima_wfpc2_x_wst,$ima_wfpc2_x_wsp,
	   $ima_wfpc2_y_wst,$ima_wfpc2_y_wsp);
    pgqvp(0,$ima_wfpc2_x_vst,$ima_wfpc2_x_vsp,
	    $ima_wfpc2_y_vst,$ima_wfpc2_y_vsp);
    pgsci(0);
    pgrect($ima_wfpc2_x_wst,$ima_wfpc2_x_wsp,
	   $ima_wfpc2_y_wst,$ima_wfpc2_y_wsp);
    pgsci(1);
    pgimag($dat_wfpc2_data,$dat_wfpc2_nx,$dat_wfpc2_ny,1,$dat_wfpc2_nx,
	   1,$dat_wfpc2_ny,$ima_wfpc2_max,$ima_wfpc2_min,$tr);
    pgbox('BCNST',0.0,0,'BCNST',0.0,0);
    # Draw 3"x3" NIFS field.
    pgsci(3);
    pgsfs(2);
    pgrect($ima_wfpc2_x_cen-1.5/$xscale,$ima_wfpc2_x_cen+1.5/$xscale,
	   $ima_wfpc2_y_cen-1.5/$yscale,$ima_wfpc2_y_cen+1.5/$yscale);
    pgsfs(1);
    # Draw NIFS FOV grid.
    if ($ima_wfpc2_grid) {
	pgsci(3);
	pgsfs(2);
	foreach $i (-60..61) {
	    $x = $ima_wfpc2_x_cen-1.5/$xscale+$i*3.0/$xscale;
	    if ($x > 0 and $x < $dat_wfpc2_nx) {
		pgmove($x,0);
		pgdraw($x,$dat_wfpc2_ny);
	    }
	}
	foreach $i (-60..61) {
	    $y = $ima_wfpc2_y_cen-1.5/$yscale+$i*3.0/$yscale;
	    if ($y > 0 and $y < $dat_wfpc2_ny) {
		pgmove(0,$y);
		pgdraw($dat_wfpc2_nx,$y);
	    }
	}
	pgsfs(1);
    }
    # Draw 60" radius ALTAIR field.
    pgsci(2);
    Plt_Circle($ima_wfpc2_x_cen,$ima_wfpc2_y_cen,60.0/$xscale);
    # Draw 90" radius OIWFS field.
    pgsci(2);
    Plt_Circle($ima_wfpc2_x_cen,$ima_wfpc2_y_cen,90.0/$xscale);
    # Draw 12.7" radius pickoff mirror field.
    pgsci(2);
    Plt_Circle($ima_wfpc2_x_cen,$ima_wfpc2_y_cen,12.7/$xscale);
    $x = $ima_wfpc2_x_cen+12.7/$xscale;
    $y = $ima_wfpc2_y_cen;
    pgmove($x,$y);
    $y = $ima_wfpc2_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    $x = $ima_wfpc2_x_cen-12.7/$xscale;
    $y = $ima_wfpc2_y_cen;
    pgmove($x,$y);
    $y = $ima_wfpc2_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    # Draw 20" radius NGS field.
    pgsci(4);
    Plt_Circle($ima_wfpc2_x_cen,$ima_wfpc2_y_cen,20.0/$xscale);
    # Draw 30" radius LGS field.
    pgsci(4);
    Plt_Circle($ima_wfpc2_x_cen,$ima_wfpc2_y_cen,30.0/$xscale);
    pgsci(1);
    # Overlay USNO stars.
    if ($dat_usno_got) {
	open (IN,"$usno") or
	    die "GS_SEARCH.PL: Cannot open input file $usno!\n";
	$size = 5/$xscale;
	$_ = <IN>;
	while (<IN>) {
	    $coord = substr($_,21,23);
	    Mark_USNO($coord,$size,$dat_wfpc2_hdr);
	}
	close (IN);
    }
    # Overlay AOWFS guide star.
    if ($dat_aowfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_aowfs_ra $dat_aowfs_dec";
	Mark_AOWFS($coord,$size,$dat_wfpc2_hdr);
    }
    # Overlay OIWFS guide star.
    if ($dat_oiwfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_oiwfs_ra $dat_oiwfs_dec";
	Mark_OIWFS($coord,$size,$dat_wfpc2_hdr);
    }
    # Draw "Zoom" button.
    Plt_Button($but_wfpc2_1_x_vst,
               $but_wfpc2_1_x_vsp,
               $but_wfpc2_1_y_vst,
	       $but_wfpc2_1_y_vsp,
	       $but_wfpc2_1_lab,
	       $but_wfpc2_1_sta);
    # Draw "Unzoom" button.
    Plt_Button($but_wfpc2_2_x_vst,
               $but_wfpc2_2_x_vsp,
               $but_wfpc2_2_y_vst,
	       $but_wfpc2_2_y_vsp,
	       $but_wfpc2_2_lab,
	       $but_wfpc2_2_sta);
    # Draw "Center" button.
    Plt_Button($but_wfpc2_3_x_vst,
               $but_wfpc2_3_x_vsp,
               $but_wfpc2_3_y_vst,
	       $but_wfpc2_3_y_vsp,
	       $but_wfpc2_3_lab,
	       $but_wfpc2_3_sta);
    # Draw "Range" button.
    Plt_Button($but_wfpc2_4_x_vst,
               $but_wfpc2_4_x_vsp,
               $but_wfpc2_4_y_vst,
	       $but_wfpc2_4_y_vsp,
	       $but_wfpc2_4_lab,
	       $but_wfpc2_4_sta);
    # Draw "Reset" button.
    Plt_Button($but_wfpc2_5_x_vst,
               $but_wfpc2_5_x_vsp,
               $but_wfpc2_5_y_vst,
	       $but_wfpc2_5_y_vsp,
	       $but_wfpc2_5_lab,
	       $but_wfpc2_5_sta);
    pgsvp(0,1,0,1);
    pgswin(0,1,0,1);
    return;
}

# Routine to plot a NICMOS image.

sub Plt_NICMOS {
    my ($fil,$ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    my ($xscale, $yscale, $coord, $size, $crota2);
    my ($tr) = [0,1,0,0,0,1];
    my ($fits) = "images/$fil/$fil"."_nicmos.fits";
    my ($usno) = "images/$fil/$fil.usno";
    $ima_nicmos_x_vst = 0.51;
    $ima_nicmos_x_vsp = 0.85;
    $ima_nicmos_y_vst = 0.02;
    $ima_nicmos_y_vsp = 0.40;
    $but_nicmos_1_x_vst = 0.86;
    $but_nicmos_1_x_vsp = 0.97;
    $but_nicmos_1_y_vst = 0.35;
    $but_nicmos_1_y_vsp = 0.40;
    $but_nicmos_1_lab = "Zoom";
    $but_nicmos_2_x_vst = 0.86;
    $but_nicmos_2_x_vsp = 0.97;
    $but_nicmos_2_y_vst = 0.27;
    $but_nicmos_2_y_vsp = 0.32;
    $but_nicmos_2_lab = "Unzoom";
    $but_nicmos_3_x_vst = 0.86;
    $but_nicmos_3_x_vsp = 0.97;
    $but_nicmos_3_y_vst = 0.19;
    $but_nicmos_3_y_vsp = 0.24;
    $but_nicmos_3_lab = "Center";
    $but_nicmos_4_x_vst = 0.86;
    $but_nicmos_4_x_vsp = 0.97;
    $but_nicmos_4_y_vst = 0.11;
    $but_nicmos_4_y_vsp = 0.16;
    $but_nicmos_4_lab = "Range";
    $but_nicmos_5_x_vst = 0.86;
    $but_nicmos_5_x_vsp = 0.97;
    $but_nicmos_5_y_vst = 0.03;
    $but_nicmos_5_y_vsp = 0.08;
    $but_nicmos_5_lab = "Reset";
    pgsci(1);                  # Set color index (default).
    pgslw(1);                  # Set line width (1=default).
    pgscf(2);                  # Set character font (1=default; 2=roman).
    pgsch(1.0);                # Set character height.
    # Draw bounding box.
    pgsvp(0.50,1.00,0.00,0.45);
    pgswin(0,1,0,1);
    pgsci(0);
    pgrect(0,1,0,1);
    pgsci(1);
    pgbox('BC',0.0,0,'BC',0.0,0);
    # Read FITS file.
    if (! $dat_nicmos_read) {
	($dat_nicmos_got,$dat_nicmos_data,$dat_nicmos_nx,$dat_nicmos_ny,
	 $dat_nicmos_hdr,$dat_nicmos_min,$dat_nicmos_max) = Read_FITS($fits);
	if ($ima_nicmos_min > $ima_nicmos_max) {
	    $ima_nicmos_min = $dat_nicmos_min;
	    $ima_nicmos_max = $dat_nicmos_max;
	}
	$dat_nicmos_read = 1;  # .true.
    }
    if (! $dat_nicmos_got) {
	pgptxt(0.5,0.92,0.0,0.5,"NICMOS");
	pgptxt(0.5,0.5,0.0,0.5,"No NICMOS image available.");
	$ima_nicmos_min = 0;
	$ima_nicmos_max = 0;
	return;
    } else {
	$title = $dat_nicmos_hdr->{'FILTER'};
	$title = substr($title,1,length($title)-2); $title =~ s/\s{1}//g;
	pgptxt(0.5,0.92,0.0,0.5,"NICMOS $title");
    }
    # Plot image.
    pgsch(0.5);
    pgsvp($ima_nicmos_x_vst,$ima_nicmos_x_vsp,
	  $ima_nicmos_y_vst,$ima_nicmos_y_vsp);
    $rh = substr($ra, 0,2);
    $rm = substr($ra, 3,2);
    $rs = substr($ra, 6,5);
    $dc = substr($dec,0,1);
    $dd = substr($dec,1,2);
    $dm = substr($dec,4,2);
    $ds = substr($dec,7,4);
    ($ima_nicmos_x_cen,$ima_nicmos_y_cen) = 
	RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$dat_nicmos_hdr);
    # Image scale in arcsec/pixel.
    $crota2 = atan2($dat_nicmos_hdr->{'CD2_1'},$dat_nicmos_hdr->{'CD1_1'});
    $xscale = abs($dat_nicmos_hdr->{'CD1_1'}/cos($crota2)*3600);
    $yscale = abs($dat_nicmos_hdr->{'CD2_2'}/cos($crota2)*3600);
    $ima_nicmos_x_wst = $ima_nicmos_x_cen+$ima_nicmos_x_off
	-90/$ima_nicmos_x_zoom/$xscale;
    $ima_nicmos_x_wsp = $ima_nicmos_x_cen+$ima_nicmos_x_off
	+90/$ima_nicmos_x_zoom/$xscale;
    $ima_nicmos_y_wst = $ima_nicmos_y_cen+$ima_nicmos_y_off
	-90/$ima_nicmos_y_zoom/$yscale;
    $ima_nicmos_y_wsp = $ima_nicmos_y_cen+$ima_nicmos_y_off
	+90/$ima_nicmos_y_zoom/$yscale;
    pgwnad($ima_nicmos_x_wst,$ima_nicmos_x_wsp,
	   $ima_nicmos_y_wst,$ima_nicmos_y_wsp);
    pgqvp(0,$ima_nicmos_x_vst,$ima_nicmos_x_vsp,
	    $ima_nicmos_y_vst,$ima_nicmos_y_vsp);
    pgsci(0);
    pgrect($ima_nicmos_x_wst,$ima_nicmos_x_wsp,
	   $ima_nicmos_y_wst,$ima_nicmos_y_wsp);
    pgsci(1);
    pgimag($dat_nicmos_data,$dat_nicmos_nx,$dat_nicmos_ny,1,$dat_nicmos_nx,
	   1,$dat_nicmos_ny,$ima_nicmos_max,$ima_nicmos_min,$tr);
    pgbox('BCNST',0.0,0,'BCNST',0.0,0);
    # Draw 3"x3" NIFS field.
    pgsci(3);
    pgsfs(2);
    pgrect($ima_nicmos_x_cen-1.5/$xscale,$ima_nicmos_x_cen+1.5/$xscale,
	   $ima_nicmos_y_cen-1.5/$yscale,$ima_nicmos_y_cen+1.5/$yscale);
    # NIFS_Grid($ima_nicmos_x_cen,$ima_nicmos_y_cen,$xscale,$yscale);
    pgsfs(1);
    # Draw NIFS FOV grid.
    if ($ima_nicmos_grid) {
	pgsci(3);
	pgsfs(2);
	foreach $i (-60..61) {
	    $x = $ima_nicmos_x_cen-1.5/$xscale+$i*3.0/$xscale;
	    if ($x > 0 and $x < $dat_nicmos_nx) {
		pgmove($x,0);
		pgdraw($x,$dat_nicmos_ny);
	    }
	}
	foreach $i (-60..61) {
	    $y = $ima_nicmos_y_cen-1.5/$yscale+$i*3.0/$yscale;
	    if ($y > 0 and $y < $dat_nicmos_ny) {
		pgmove(0,$y);
		pgdraw($dat_nicmos_nx,$y);
	    }
	}
	pgsfs(1);
    }
    # Draw 60" radius ALTAIR field.
    pgsci(2);
    Plt_Circle($ima_nicmos_x_cen,$ima_nicmos_y_cen,60.0/$xscale);
    # Draw 90" radius OIWFS field.
    pgsci(2);
    Plt_Circle($ima_nicmos_x_cen,$ima_nicmos_y_cen,90.0/$xscale);
    # Draw 12.7" radius pickoff mirror field.
    pgsci(2);
    Plt_Circle($ima_nicmos_x_cen,$ima_nicmos_y_cen,12.7/$xscale);
    $x = $ima_nicmos_x_cen+12.7/$xscale;
    $y = $ima_nicmos_y_cen;
    pgmove($x,$y);
    $y = $ima_nicmos_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    $x = $ima_nicmos_x_cen-12.7/$xscale;
    $y = $ima_nicmos_y_cen;
    pgmove($x,$y);
    $y = $ima_nicmos_y_cen-90.0/$yscale;
    pgdraw($x,$y);
    # Draw 20" radius NGS field.
    pgsci(4);
    Plt_Circle($ima_nicmos_x_cen,$ima_nicmos_y_cen,20.0/$xscale);
    # Draw 30" radius LGS field.
    pgsci(4);
    Plt_Circle($ima_nicmos_x_cen,$ima_nicmos_y_cen,30.0/$xscale);
    pgsci(1);
    # Overlay USNO stars.
    if ($dat_usno_got) {
	open (IN,"$usno") or
	    die "GS_SEARCH.PL: Cannot open input file $usno!\n";
	$size = 5/$xscale;
	$_ = <IN>;
	while (<IN>) {
	    $coord = substr($_,21,23);
	    Mark_USNO($coord,$size,$dat_nicmos_hdr);
	}
	close (IN);
    }
    # Overlay AOWFS guide star.
    if ($dat_aowfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_aowfs_ra $dat_aowfs_dec";
	Mark_AOWFS($coord,$size,$dat_nicmos_hdr);
    }
    # Overlay OIWFS guide star.
    if ($dat_oiwfs_got) {
	$size = 3/$xscale;
	$coord = "$dat_oiwfs_ra $dat_oiwfs_dec";
	Mark_OIWFS($coord,$size,$dat_nicmos_hdr);
    }
    # Draw "Zoom" button.
    Plt_Button($but_nicmos_1_x_vst,
               $but_nicmos_1_x_vsp,
               $but_nicmos_1_y_vst,
	       $but_nicmos_1_y_vsp,
	       $but_nicmos_1_lab,
	       $but_nicmos_1_sta);
    # Draw "Unzoom" button.
    Plt_Button($but_nicmos_2_x_vst,
               $but_nicmos_2_x_vsp,
               $but_nicmos_2_y_vst,
	       $but_nicmos_2_y_vsp,
	       $but_nicmos_2_lab,
	       $but_nicmos_2_sta);
    # Draw "Center" button.
    Plt_Button($but_nicmos_3_x_vst,
               $but_nicmos_3_x_vsp,
               $but_nicmos_3_y_vst,
	       $but_nicmos_3_y_vsp,
	       $but_nicmos_3_lab,
	       $but_nicmos_3_sta);
    # Draw "Range" button.
    Plt_Button($but_nicmos_4_x_vst,
               $but_nicmos_4_x_vsp,
               $but_nicmos_4_y_vst,
	       $but_nicmos_4_y_vsp,
	       $but_nicmos_4_lab,
	       $but_nicmos_4_sta);
    # Draw "Reset" button.
    Plt_Button($but_nicmos_5_x_vst,
               $but_nicmos_5_x_vsp,
               $but_nicmos_5_y_vst,
	       $but_nicmos_5_y_vsp,
	       $but_nicmos_5_lab,
	       $but_nicmos_5_sta);
    pgsvp(0,1,0,1);
    pgswin(0,1,0,1);
    return;
}

# Routine to interactively adjust plot parameters.

sub Adjust_Plt {
    my ($fil) = @_;
    my ($x,$y,$key,$tmp);
    my ($tab, $con, $bri, $sign);
    my ($px,$py,$val,$wav,$f0,$cam,$rh,$rm,$rs,$dc,$dd,$dm,$ds);
    my ($new_ra, $new_dec);
    pgsvp(0,1,0,1);
    pgswin(0,1,0,1);
    $x = ($but_title_3_x_vsp+$but_title_3_x_vst)/2;
    $y = ($but_title_3_y_vsp+$but_title_3_y_vst)/2;
    pgcurs($x,$y,$key);
    while ($key ne "n") {
	# Title button 1.
	if ($x > $but_title_1_x_vst and $x < $but_title_1_x_vsp and
            $y > $but_title_1_y_vst and $y < $but_title_1_y_vsp) {
	    if ($but_title_1_sta == 0) {
		$but_title_1_sta = 1;
		Plt_Button($but_title_1_x_vst,
			   $but_title_1_x_vsp,
			   $but_title_1_y_vst,
			   $but_title_1_y_vsp,
			   $but_title_1_lab,
			   $but_title_1_sta);

		$x = 0.5;
		$y = 0.1;
		$tab = $col_tab;
		$con = $col_con;
		$bri = $col_bri;
		$sign = 1;
		while ($key ne "q" and $key ne "Q") {
		    pgcurs($x,$y,$key);
		    if ($key eq "q" or $key eq "Q") {
			next;
		    } elsif ($key eq "?") {
			print "Use cursor to adjust color table:\n".
			    "   Key T cycles through available color tables.\n".
			    "   Keys 1,2,3,4,5 select different color tables.\n".
			    "   Key C changes contrast and brightness, with:\n".
			    "      Cursor x position setting brightness and\n".
			    "      Cursor y position setting contrast\n".
			    "   Hold down C key while moving cursor to change\n".
			    "      contrast and brightness continuously.\n".
                            "   Key R resets contrast=1.0 and brightness=0.5.\n".
		            "   Key - reverses color palette.\n";
		    } elsif ($key eq "c" or $key eq "C") {
			$bri = $x;
			if ($bri < 0) {$bri = 0;}
			if ($bri > 1) {$bri = 1;}
			$con = $y;
			if ($con < 0) {$con = 0;}
			if ($con > 1) {$con = 1;}
		    } elsif ($key eq "r" or $key eq "R") {
			$bri = 0.5;
			$con = 0.1;
			$x = 0.5;
			$y = 0.1;
		    } elsif ($key eq "-") {
			$sign *= -1;
		    } elsif ($key eq "1") {
			$tab = 1;
		    } elsif ($key eq "2") {
			$tab = 2;
		    } elsif ($key eq "3") {
			$tab = 3;
		    } elsif ($key eq "4") {
			$tab = 4;
		    } elsif ($key eq "5") {
			$tab = 5;
		    } elsif ($key eq "t" or $key eq "T") {
			$tab += 1;
			if ($tab > 5) {$tab = 1;}
		    } elsif ($x > $but_title_1_x_vst and 
			     $x < $but_title_1_x_vsp and
			     $y > $but_title_1_y_vst and 
			     $y < $but_title_1_y_vsp) {
			$key = "q";
			next;
		    } else {
			next;
		    }
		    $col_tab = $tab;
		    $col_con = $sign*$con;
		    $col_bri = $bri;
		    Color_Table($col_tab,$col_con,$col_bri);
		}
		$but_title_1_sta = 0;
		Plt_Button($but_title_1_x_vst,
			   $but_title_1_x_vsp,
			   $but_title_1_y_vst,
			   $but_title_1_y_vsp,
			   $but_title_1_lab,
			   $but_title_1_sta);
	    }
	}
	# Title button 2.
	if ($x > $but_title_2_x_vst and $x < $but_title_2_x_vsp and
            $y > $but_title_2_y_vst and $y < $but_title_2_y_vsp) {
	    if ($but_title_2_sta == 0) {
		$but_title_2_sta = 1;
		Plt_Button($but_title_2_x_vst,
			   $but_title_2_x_vsp,
			   $but_title_2_y_vst,
			   $but_title_2_y_vsp,
			   $but_title_2_lab,
			   $but_title_2_sta);
		# Plot to postscript file.
		Display_Images($fil,$ra,$dec,2);
		# Reset plot device to screen.
		pgslct($pltid);
		# Send postscript file to printer.
		if ($printer eq "") {
		    system("lpr images/$fil/$fil.ps");
		} else {
		    system("lpr -P$printer images/$fil/$fil.ps");
		}
		$but_title_2_sta = 0;
		Plt_Button($but_title_2_x_vst,
			   $but_title_2_x_vsp,
			   $but_title_2_y_vst,
			   $but_title_2_y_vsp,
			   $but_title_2_lab,
			   $but_title_2_sta);
	    }
	}
	# Title button 3.
	if ($x > $but_title_3_x_vst and $x < $but_title_3_x_vsp and
            $y > $but_title_3_y_vst and $y < $but_title_3_y_vsp) {
	    $key = "n";
	    if ($but_title_3_sta == 0) {
		$but_title_3_sta = 1;
		Plt_Button($but_title_3_x_vst,
			   $but_title_3_x_vsp,
			   $but_title_3_y_vst,
			   $but_title_3_y_vsp,
			   $but_title_3_lab,
			   $but_title_3_sta);
		next;
	    }
	}
	# Title button 4.
	if ($x > $but_title_4_x_vst and $x < $but_title_4_x_vsp and
            $y > $but_title_4_y_vst and $y < $but_title_4_y_vsp) {
	    # Write object data file.
	    Write_Data($fil);
            # Report NGS and LGS Y,?,N statistics.
	    if ($ncod) {
		print "\nGuide Star Statistics:\n";
		print "NGS system: Y=$ngs[0]; ?=$ngs[1]; N=$ngs[2]\n"; 
		print "LGS system: Y=$lgs[0]; ?=$lgs[1]; N=$lgs[2]\n\n";
	    }
	    exit;
	}
	# DSS2 image.
	if ($x > $ima_dss2_x_vst and $x < $ima_dss2_x_vsp and
            $y > $ima_dss2_y_vst and $y < $ima_dss2_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($key eq "A") {
                # Recenter display.
		$ima_dss2_x_off = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst)-$ima_dss2_x_cen;
		$ima_dss2_y_off = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst)-$ima_dss2_y_cen;
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		pgebuf;
	    } elsif ($key eq "X") {
                # Print RA and Dec.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
		    XY2RaDec_CD($px,$py,$dat_dss2_hdr);
		print "                $rh:$rm:$rs $dc$dd:$dm:$ds";
		if ($px < 0 or $px > $dat_dss2_nx or
                    $py < 0 or $py > $dat_dss2_ny) {
		    print "\n";
		} else {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_dss2_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "  $px $py $val\n";
		}
	    } elsif ($key eq "D") {
                # Change display center coordinate.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		if ($px > 0 and $px < $dat_dss2_nx or
                    $py > 0 and $py < $dat_dss2_ny) {
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_dss2_hdr);
		    $ra = "$rh:$rm:$rs";
		    $dec = "$dc$dd:$dm:$ds";
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_dss2_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "                $ra $dec  $px $py $val\n";
		    # Replot display.
		    $ima_dss2_x_off = 0;
		    $ima_dss2_y_off = 0;
		    $ima_2mass_x_off = 0;
		    $ima_2mass_y_off = 0;
		    $ima_wfpc2_x_off = 0;
		    $ima_wfpc2_y_off = 0;
		    $ima_nicmos_x_off = 0;
		    $ima_nicmos_y_off = 0;
		    pgbbuf;
		    Plt_Title($obj,$ra,$dec);
		    Plt_DSS2_R($fil,$ra,$dec);
		    Plt_2MASS_K($fil,$ra,$dec);
		    Plt_WFPC2($fil,$ra,$dec);
		    Plt_NICMOS($fil,$ra,$dec);
		    pgsvp(0,1,0,1);
		    pgswin(0,1,0,1);
		    pgebuf;
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "s") {
                # Set sky value.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		if ($px > 0 and $px < $dat_dss2_nx or
                    $py > 0 and $py < $dat_dss2_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $ima_dss2_sky = $dat_dss2_data->[$py][$px];
		    print "Sky value = $ima_dss2_sky\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "m") {
                # Report magnitude.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		if ($px > 0 and $px < $dat_dss2_nx or
                    $py > 0 and $py < $dat_dss2_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_dss2_data->[$py][$px];
		    $val = -2.5*log10($val-$ima_dss2_sky);
#			+$dat_dss2_hdr->{'MAGZP'};
		    print "Surface brightness = $val magnitudes/pixel.\n";
		    $val = $val-2.5*log10(abs($dat_dss2_hdr->{'CDELT1'})*3600*
					  abs($dat_dss2_hdr->{'CDELT2'})*3600);
		    print "                   = $val magnitudes/arcsec^2.\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "a") {
                # Mark AOWFS star.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		if ($px > 0 and $px < $dat_dss2_nx or
                    $py > 0 and $py < $dat_dss2_ny) {
		    # Get AOWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_dss2_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_aowfs_ra and
			$new_dec ne $dat_aowfs_dec) {
			$dat_aowfs_got = 1;
			$dat_aowfs_ra = $new_ra;
			$dat_aowfs_dec = $new_dec;
		    } else {
			$dat_aowfs_got = 0;
			$dat_aowfs_ra = -100;
			$dat_aowfs_dec = -100;
		    }
		} else {
		    $dat_aowfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "o") {
                # Mark OIWFS star.
		$px = $ima_dss2_x_wst+($x-$ima_dss2_x_vst)/
		    ($ima_dss2_x_vsp-$ima_dss2_x_vst)*
		    ($ima_dss2_x_wsp-$ima_dss2_x_wst);
		$py = $ima_dss2_y_wst+($y-$ima_dss2_y_vst)/
		    ($ima_dss2_y_vsp-$ima_dss2_y_vst)*
		    ($ima_dss2_y_wsp-$ima_dss2_y_wst);
		if ($px > 0 and $px < $dat_dss2_nx or
                    $py > 0 and $py < $dat_dss2_ny) {
		    # Get OIWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_dss2_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_oiwfs_ra and
			$new_dec ne $dat_oiwfs_dec) {
			$dat_oiwfs_got = 1;
			$dat_oiwfs_ra = $new_ra;
			$dat_oiwfs_dec = $new_dec;
		    } else {
			$dat_oiwfs_got = 0;
			$dat_oiwfs_ra = -100;
			$dat_oiwfs_dec = -100;
		    }
		} else {
		    $dat_oiwfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "g") {
                # Draw FOV grid.
		if ($ima_dss2_grid) {
		    $ima_dss2_grid = 0;
		} else {
		    $ima_dss2_grid = 1;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } else {
		print "$key\n";
	    }
	}
	# DSS2 button 1.
	if ($x > $but_dss2_1_x_vst and $x < $but_dss2_1_x_vsp and
            $y > $but_dss2_1_y_vst and $y < $but_dss2_1_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($but_dss2_1_sta == 0) {
		$but_dss2_1_sta = 1;
		Plt_Button($but_dss2_1_x_vst,
			   $but_dss2_1_x_vsp,
			   $but_dss2_1_y_vst,
			   $but_dss2_1_y_vsp,
			   $but_dss2_1_lab,
			   $but_dss2_1_sta);
		pgbbuf;
		$ima_dss2_x_zoom *= 2;
		$ima_dss2_y_zoom *= 2;
		Plt_DSS2_R($fil,$ra,$dec);
		$but_dss2_1_sta = 0;
                pgebuf;
		Plt_Button($but_dss2_1_x_vst,
			   $but_dss2_1_x_vsp,
			   $but_dss2_1_y_vst,
			   $but_dss2_1_y_vsp,
			   $but_dss2_1_lab,
			   $but_dss2_1_sta);
	    }
	}
	# DSS2 button 2.
	if ($x > $but_dss2_2_x_vst and $x < $but_dss2_2_x_vsp and
            $y > $but_dss2_2_y_vst and $y < $but_dss2_2_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($but_dss2_2_sta == 0) {
		$but_dss2_2_sta = 1;
		Plt_Button($but_dss2_2_x_vst,
			   $but_dss2_2_x_vsp,
			   $but_dss2_2_y_vst,
			   $but_dss2_2_y_vsp,
			   $but_dss2_2_lab,
			   $but_dss2_2_sta);
		pgbbuf;
		$ima_dss2_x_zoom /= 2;
		$ima_dss2_y_zoom /= 2;
		Plt_DSS2_R($fil,$ra,$dec);
		$but_dss2_2_sta = 0;
		pgebuf;
		Plt_Button($but_dss2_2_x_vst,
			   $but_dss2_2_x_vsp,
			   $but_dss2_2_y_vst,
			   $but_dss2_2_y_vsp,
			   $but_dss2_2_lab,
			   $but_dss2_2_sta);
	    }
	}
	# DSS2 button 3.
	if ($x > $but_dss2_3_x_vst and $x < $but_dss2_3_x_vsp and
            $y > $but_dss2_3_y_vst and $y < $but_dss2_3_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($but_dss2_3_sta == 0) {
		$but_dss2_3_sta = 1;
		Plt_Button($but_dss2_3_x_vst,
			   $but_dss2_3_x_vsp,
			   $but_dss2_3_y_vst,
			   $but_dss2_3_y_vsp,
			   $but_dss2_3_lab,
			   $but_dss2_3_sta);
		pgbbuf;
		$ima_dss2_x_off = 0;
		$ima_dss2_y_off = 0;
		Plt_DSS2_R($fil,$ra,$dec);
		pgebuf;
		$but_dss2_3_sta = 0;
		Plt_Button($but_dss2_3_x_vst,
			   $but_dss2_3_x_vsp,
			   $but_dss2_3_y_vst,
			   $but_dss2_3_y_vsp,
			   $but_dss2_3_lab,
			   $but_dss2_3_sta);
	    }
	}
	# DSS2 button 4.
	if ($x > $but_dss2_4_x_vst and $x < $but_dss2_4_x_vsp and
            $y > $but_dss2_4_y_vst and $y < $but_dss2_4_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($but_dss2_4_sta == 0) {
		$but_dss2_4_sta = 1;
		Plt_Button($but_dss2_4_x_vst,
			   $but_dss2_4_x_vsp,
			   $but_dss2_4_y_vst,
			   $but_dss2_4_y_vsp,
			   $but_dss2_4_lab,
			   $but_dss2_4_sta);
		print "Enter minimum value [$ima_dss2_min]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_dss2_min = $tmp;
		}
		print "Enter maximum value [$ima_dss2_max]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_dss2_max = $tmp;
		}
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		pgebuf;
		$but_dss2_4_sta = 0;
		Plt_Button($but_dss2_4_x_vst,
			   $but_dss2_4_x_vsp,
			   $but_dss2_4_y_vst,
			   $but_dss2_4_y_vsp,
			   $but_dss2_4_lab,
			   $but_dss2_4_sta);
	    }
	}
	# DSS2 button 5.
	if ($x > $but_dss2_5_x_vst and $x < $but_dss2_5_x_vsp and
            $y > $but_dss2_5_y_vst and $y < $but_dss2_5_y_vsp) {
	    if (! $dat_dss2_got) {next;}
	    if ($but_dss2_5_sta == 0) {
		$but_dss2_5_sta = 1;
		Plt_Button($but_dss2_5_x_vst,
			   $but_dss2_5_x_vsp,
			   $but_dss2_5_y_vst,
			   $but_dss2_5_y_vsp,
			   $but_dss2_5_lab,
			   $but_dss2_5_sta);
		pgbbuf;
		$col_tab = 1;
		$col_con = 0.1;
		$col_bri = 0.5;
		Color_Table($col_tab,$col_con,$col_bri);
		$ima_dss2_x_off = 0;
		$ima_dss2_y_off = 0;
		$ima_dss2_x_zoom = 1;
		$ima_dss2_y_zoom = 1;
		$ima_dss2_min = $dat_dss2_min;
		$ima_dss2_max = $dat_dss2_max;
		Plt_DSS2_R($fil,$ra,$dec);
		$but_dss2_5_sta = 0;
		pgebuf;
		Plt_Button($but_dss2_5_x_vst,
			   $but_dss2_5_x_vsp,
			   $but_dss2_5_y_vst,
			   $but_dss2_5_y_vsp,
			   $but_dss2_5_lab,
			   $but_dss2_5_sta);
	    }
	}
	# 2MASS image.
	if ($x > $ima_2mass_x_vst and $x < $ima_2mass_x_vsp and
            $y > $ima_2mass_y_vst and $y < $ima_2mass_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($key eq "A") {
                # Recenter display.
		$ima_2mass_x_off = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst)-$ima_2mass_x_cen;
		$ima_2mass_y_off = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst)-$ima_2mass_y_cen;
		pgbbuf;
		Plt_2MASS_K($fil,$ra,$dec);
		pgebuf;
	    } elsif ($key eq "X") {
                # Print RA and Dec.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
		    XY2RaDec_CD($px,$py,$dat_2mass_hdr);
		print "                $rh:$rm:$rs $dc$dd:$dm:$ds";
		if ($px < 0 or $px > $dat_2mass_nx or
                    $py < 0 or $py > $dat_2mass_ny) {
		    print "\n";
		} else {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_2mass_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "  $px $py $val\n";
		}
	    } elsif ($key eq "D") {
                # Change display center coordinate.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		if ($px > 0 and $px < $dat_2mass_nx or
                    $py > 0 and $py < $dat_2mass_ny) {
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_2mass_hdr);
		    $ra = "$rh:$rm:$rs";
		    $dec = "$dc$dd:$dm:$ds";
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_2mass_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "                $ra $dec  $px $py $val\n";
		    # Replot display.
		    $ima_dss2_x_off = 0;
		    $ima_dss2_y_off = 0;
		    $ima_2mass_x_off = 0;
		    $ima_2mass_y_off = 0;
		    $ima_wfpc2_x_off = 0;
		    $ima_wfpc2_y_off = 0;
		    $ima_nicmos_x_off = 0;
		    $ima_nicmos_y_off = 0;
		    pgbbuf;
		    Plt_Title($obj,$ra,$dec);
		    Plt_DSS2_R($fil,$ra,$dec);
		    Plt_2MASS_K($fil,$ra,$dec);
		    Plt_WFPC2($fil,$ra,$dec);
		    Plt_NICMOS($fil,$ra,$dec);
		    pgsvp(0,1,0,1);
		    pgswin(0,1,0,1);
		    pgebuf;
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "s") {
                # Set sky value.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		if ($px > 0 and $px < $dat_2mass_nx or
                    $py > 0 and $py < $dat_2mass_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $ima_2mass_sky = $dat_2mass_data->[$py][$px];
		    print "Sky value = $ima_2mass_sky\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "m") {
                # Report magnitude.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		if ($px > 0 and $px < $dat_2mass_nx or
                    $py > 0 and $py < $dat_2mass_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_2mass_data->[$py][$px];
		    $val = -2.5*log10($val-$ima_2mass_sky)+
			$dat_2mass_hdr->{'MAGZP'};
		    print "Surface brightness = $val magnitudes/pixel.\n";
		    $val = $val-2.5*log10(abs($dat_2mass_hdr->{'CDELT1'})*3600*
					  abs($dat_2mass_hdr->{'CDELT2'})*3600);
		    print "                   = $val magnitudes/arcsec^2.\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "a") {
                # Mark AOWFS star.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		if ($px > 0 and $px < $dat_2mass_nx or
                    $py > 0 and $py < $dat_2mass_ny) {
		    # Get AOWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_2mass_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_aowfs_ra and
			$new_dec ne $dat_aowfs_dec) {
			$dat_aowfs_got = 1;
			$dat_aowfs_ra = $new_ra;
			$dat_aowfs_dec = $new_dec;
		    } else {
			$dat_aowfs_got = 0;
			$dat_aowfs_ra = -100;
			$dat_aowfs_dec = -100;
		    }
		} else {
		    $dat_aowfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "o") {
                # Mark OIWFS star.
		$px = $ima_2mass_x_wst+($x-$ima_2mass_x_vst)/
		    ($ima_2mass_x_vsp-$ima_2mass_x_vst)*
		    ($ima_2mass_x_wsp-$ima_2mass_x_wst);
		$py = $ima_2mass_y_wst+($y-$ima_2mass_y_vst)/
		    ($ima_2mass_y_vsp-$ima_2mass_y_vst)*
		    ($ima_2mass_y_wsp-$ima_2mass_y_wst);
		if ($px > 0 and $px < $dat_2mass_nx or
                    $py > 0 and $py < $dat_2mass_ny) {
		    # Get OIWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_2mass_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_oiwfs_ra and
			$new_dec ne $dat_oiwfs_dec) {
			$dat_oiwfs_got = 1;
			$dat_oiwfs_ra = $new_ra;
			$dat_oiwfs_dec = $new_dec;
		    } else {
			$dat_oiwfs_got = 0;
			$dat_oiwfs_ra = -100;
			$dat_oiwfs_dec = -100;
		    }
		} else {
		    $dat_oiwfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "g") {
                # Draw FOV grid.
		if ($ima_2mass_grid) {
		    $ima_2mass_grid = 0;
		} else {
		    $ima_2mass_grid = 1;
		}
		# Replot display.
		pgbbuf;
		Plt_2MASS_K($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } else {
		print "$key\n";
	    }
	}
	# 2MASS button 1.
	if ($x > $but_2mass_1_x_vst and $x < $but_2mass_1_x_vsp and
            $y > $but_2mass_1_y_vst and $y < $but_2mass_1_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($but_2mass_1_sta == 0) {
		$but_2mass_1_sta = 1;
		Plt_Button($but_2mass_1_x_vst,
			   $but_2mass_1_x_vsp,
			   $but_2mass_1_y_vst,
			   $but_2mass_1_y_vsp,
			   $but_2mass_1_lab,
			   $but_2mass_1_sta);
		pgbbuf;
		$ima_2mass_x_zoom *= 2;
		$ima_2mass_y_zoom *= 2;
		Plt_2MASS_K($fil,$ra,$dec);
		$but_2mass_1_sta = 0;
		pgebuf;
		Plt_Button($but_2mass_1_x_vst,
			   $but_2mass_1_x_vsp,
			   $but_2mass_1_y_vst,
			   $but_2mass_1_y_vsp,
			   $but_2mass_1_lab,
			   $but_2mass_1_sta);
	    }
	}
	# 2MASS button 2.
	if ($x > $but_2mass_2_x_vst and $x < $but_2mass_2_x_vsp and
            $y > $but_2mass_2_y_vst and $y < $but_2mass_2_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($but_2mass_2_sta == 0) {
		$but_2mass_2_sta = 1;
		Plt_Button($but_2mass_2_x_vst,
			   $but_2mass_2_x_vsp,
			   $but_2mass_2_y_vst,
			   $but_2mass_2_y_vsp,
			   $but_2mass_2_lab,
			   $but_2mass_2_sta);
		pgbbuf;
		$ima_2mass_x_zoom /= 2;
		$ima_2mass_y_zoom /= 2;
		Plt_2MASS_K($fil,$ra,$dec);
		$but_2mass_2_sta = 0;
		pgebuf;
		Plt_Button($but_2mass_2_x_vst,
			   $but_2mass_2_x_vsp,
			   $but_2mass_2_y_vst,
			   $but_2mass_2_y_vsp,
			   $but_2mass_2_lab,
			   $but_2mass_2_sta);
	    }
	}
	# 2MASS button 3.
	if ($x > $but_2mass_3_x_vst and $x < $but_2mass_3_x_vsp and
            $y > $but_2mass_3_y_vst and $y < $but_2mass_3_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($but_2mass_3_sta == 0) {
		$but_2mass_3_sta = 1;
		Plt_Button($but_2mass_3_x_vst,
			   $but_2mass_3_x_vsp,
			   $but_2mass_3_y_vst,
			   $but_2mass_3_y_vsp,
			   $but_2mass_3_lab,
			   $but_2mass_3_sta);
		pgbbuf;
		$ima_2mass_x_off = 0;
		$ima_2mass_y_off = 0;
		Plt_2MASS_K($fil,$ra,$dec);
		pgebuf;
		$but_2mass_3_sta = 0;
		Plt_Button($but_2mass_3_x_vst,
			   $but_2mass_3_x_vsp,
			   $but_2mass_3_y_vst,
			   $but_2mass_3_y_vsp,
			   $but_2mass_3_lab,
			   $but_2mass_3_sta);
	    }
	}
	# 2MASS button 4.
	if ($x > $but_2mass_4_x_vst and $x < $but_2mass_4_x_vsp and
            $y > $but_2mass_4_y_vst and $y < $but_2mass_4_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($but_2mass_4_sta == 0) {
		$but_2mass_4_sta = 1;
		Plt_Button($but_2mass_4_x_vst,
			   $but_2mass_4_x_vsp,
			   $but_2mass_4_y_vst,
			   $but_2mass_4_y_vsp,
			   $but_2mass_4_lab,
			   $but_2mass_4_sta);
		print "Enter minimum value [$ima_2mass_min]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_2mass_min = $tmp;
		}
		print "Enter maximum value [$ima_2mass_max]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_2mass_max = $tmp;
		}
		pgbbuf;
		Plt_2MASS_K($fil,$ra,$dec);
		pgebuf;
		$but_2mass_4_sta = 0;
		Plt_Button($but_2mass_4_x_vst,
			   $but_2mass_4_x_vsp,
			   $but_2mass_4_y_vst,
			   $but_2mass_4_y_vsp,
			   $but_2mass_4_lab,
			   $but_2mass_4_sta);
	    }
	}
	# 2MASS button 5.
	if ($x > $but_2mass_5_x_vst and $x < $but_2mass_5_x_vsp and
            $y > $but_2mass_5_y_vst and $y < $but_2mass_5_y_vsp) {
	    if (! $dat_2mass_got) {next;}
	    if ($but_2mass_5_sta == 0) {
		$but_2mass_5_sta = 1;
		Plt_Button($but_2mass_5_x_vst,
			   $but_2mass_5_x_vsp,
			   $but_2mass_5_y_vst,
			   $but_2mass_5_y_vsp,
			   $but_2mass_5_lab,
			   $but_2mass_5_sta);
		pgbbuf;
		$col_tab = 1;
		$col_con = 0.1;
		$col_bri = 0.5;
		Color_Table($col_tab,$col_con,$col_bri);
		$ima_2mass_x_off = 0;
		$ima_2mass_y_off = 0;
		$ima_2mass_x_zoom = 1;
		$ima_2mass_y_zoom = 1;
		$ima_2mass_min = $dat_2mass_min;
		$ima_2mass_max = $dat_2mass_max;
		Plt_2MASS_K($fil,$ra,$dec);
		$but_2mass_5_sta = 0;
		pgebuf;
		Plt_Button($but_2mass_5_x_vst,
			   $but_2mass_5_x_vsp,
			   $but_2mass_5_y_vst,
			   $but_2mass_5_y_vsp,
			   $but_2mass_5_lab,
			   $but_2mass_5_sta);
	    }
	}
	# WFPC2 image.
	if ($x > $ima_wfpc2_x_vst and $x < $ima_wfpc2_x_vsp and
            $y > $ima_wfpc2_y_vst and $y < $ima_wfpc2_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($key eq "A") {
                # Recenter display.
		$ima_wfpc2_x_off = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst)-$ima_wfpc2_x_cen;
		$ima_wfpc2_y_off = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst)-$ima_wfpc2_y_cen;
		pgbbuf;
		Plt_WFPC2($fil,$ra,$dec);
		pgebuf;
	    } elsif ($key eq "X") {
                # Print RA and Dec.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
		    XY2RaDec_CD($px,$py,$dat_wfpc2_hdr);
		print "                $rh:$rm:$rs $dc$dd:$dm:$ds";
		if ($px < 0 or $px > $dat_wfpc2_nx or
                    $py < 0 or $py > $dat_wfpc2_ny) {
		    print "\n";
		} else {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_wfpc2_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "  $px $py $val\n";
		}
	    } elsif ($key eq "D") {
                # Change display center coordinate.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		if ($px > 0 and $px < $dat_wfpc2_nx or
                    $py > 0 and $py < $dat_wfpc2_ny) {
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_wfpc2_hdr);
		    $ra = "$rh:$rm:$rs";
		    $dec = "$dc$dd:$dm:$ds";
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_wfpc2_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "                $ra $dec  $px $py $val\n";
		    # Replot display.
		    $ima_dss2_x_off = 0;
		    $ima_dss2_y_off = 0;
		    $ima_2mass_x_off = 0;
		    $ima_2mass_y_off = 0;
		    $ima_wfpc2_x_off = 0;
		    $ima_wfpc2_y_off = 0;
		    $ima_nicmos_x_off = 0;
		    $ima_nicmos_y_off = 0;
		    pgbbuf;
		    Plt_Title($obj,$ra,$dec);
		    Plt_DSS2_R($fil,$ra,$dec);
		    Plt_2MASS_K($fil,$ra,$dec);
		    Plt_WFPC2($fil,$ra,$dec);
		    Plt_NICMOS($fil,$ra,$dec);
		    pgsvp(0,1,0,1);
		    pgswin(0,1,0,1);
		    pgebuf;
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "s") {
                # Set sky value.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		if ($px > 0 and $px < $dat_wfpc2_nx or
                    $py > 0 and $py < $dat_wfpc2_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $ima_wfpc2_sky = $dat_wfpc2_data->[$py][$px];
		    print "Sky value = $ima_wfpc2_sky\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "m") {
                # Report magnitude.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		if ($px > 0 and $px < $dat_wfpc2_nx or
                    $py > 0 and $py < $dat_wfpc2_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_wfpc2_data->[$py][$px];
		    $val = -2.5*log10($val-$ima_wfpc2_sky)+
			$dat_wfpc2_hdr->{'PHOTZPT'};
		    print "Surface brightness = $val magnitudes/pixel.\n";
#		    $val = $val-2.5*log10(abs($dat_wfpc2_hdr->{'CDELT1'})*3600*
#					  abs($dat_wfpc2_hdr->{'CDELT2'})*3600);
#		    print "                   = $val magnitudes/arcsec^2.\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "a") {
                # Mark AOWFS star.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		if ($px > 0 and $px < $dat_wfpc2_nx or
                    $py > 0 and $py < $dat_wfpc2_ny) {
		    # Get AOWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_wfpc2_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_aowfs_ra and
			$new_dec ne $dat_aowfs_dec) {
			$dat_aowfs_got = 1;
			$dat_aowfs_ra = $new_ra;
			$dat_aowfs_dec = $new_dec;
		    } else {
			$dat_aowfs_got = 0;
			$dat_aowfs_ra = -100;
			$dat_aowfs_dec = -100;
		    }
		} else {
		    $dat_aowfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "o") {
                # Mark OIWFS star.
		$px = $ima_wfpc2_x_wst+($x-$ima_wfpc2_x_vst)/
		    ($ima_wfpc2_x_vsp-$ima_wfpc2_x_vst)*
		    ($ima_wfpc2_x_wsp-$ima_wfpc2_x_wst);
		$py = $ima_wfpc2_y_wst+($y-$ima_wfpc2_y_vst)/
		    ($ima_wfpc2_y_vsp-$ima_wfpc2_y_vst)*
		    ($ima_wfpc2_y_wsp-$ima_wfpc2_y_wst);
		if ($px > 0 and $px < $dat_wfpc2_nx or
                    $py > 0 and $py < $dat_wfpc2_ny) {
		    # Get OIWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_wfpc2_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_oiwfs_ra and
			$new_dec ne $dat_oiwfs_dec) {
			$dat_oiwfs_got = 1;
			$dat_oiwfs_ra = $new_ra;
			$dat_oiwfs_dec = $new_dec;
		    } else {
			$dat_oiwfs_got = 0;
			$dat_oiwfs_ra = -100;
			$dat_oiwfs_dec = -100;
		    }
		} else {
		    $dat_oiwfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "g") {
                # Draw FOV grid.
		if ($ima_wfpc2_grid) {
		    $ima_wfpc2_grid = 0;
		} else {
		    $ima_wfpc2_grid = 1;
		}
		# Replot display.
		pgbbuf;
		Plt_WFPC2($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } else {
		print "$key\n";
	    }
	}
	# WFPC2 button 1.
	if ($x > $but_wfpc2_1_x_vst and $x < $but_wfpc2_1_x_vsp and
            $y > $but_wfpc2_1_y_vst and $y < $but_wfpc2_1_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($but_wfpc2_1_sta == 0) {
		$but_wfpc2_1_sta = 1;
		Plt_Button($but_wfpc2_1_x_vst,
			   $but_wfpc2_1_x_vsp,
			   $but_wfpc2_1_y_vst,
			   $but_wfpc2_1_y_vsp,
			   $but_wfpc2_1_lab,
			   $but_wfpc2_1_sta);
		pgbbuf;
		$ima_wfpc2_x_zoom *= 2;
		$ima_wfpc2_y_zoom *= 2;
		Plt_WFPC2($fil,$ra,$dec);
		$but_wfpc2_1_sta = 0;
		pgebuf;
		Plt_Button($but_wfpc2_1_x_vst,
			   $but_wfpc2_1_x_vsp,
			   $but_wfpc2_1_y_vst,
			   $but_wfpc2_1_y_vsp,
			   $but_wfpc2_1_lab,
			   $but_wfpc2_1_sta);
	    }
	}
	# WFPC2 button 2.
	if ($x > $but_wfpc2_2_x_vst and $x < $but_wfpc2_2_x_vsp and
            $y > $but_wfpc2_2_y_vst and $y < $but_wfpc2_2_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($but_wfpc2_2_sta == 0) {
		$but_wfpc2_2_sta = 1;
		Plt_Button($but_wfpc2_2_x_vst,
			   $but_wfpc2_2_x_vsp,
			   $but_wfpc2_2_y_vst,
			   $but_wfpc2_2_y_vsp,
			   $but_wfpc2_2_lab,
			   $but_wfpc2_2_sta);
		pgbbuf;
		$ima_wfpc2_x_zoom /= 2;
		$ima_wfpc2_y_zoom /= 2;
		Plt_WFPC2($fil,$ra,$dec);
		$but_wfpc2_2_sta = 0;
		pgebuf;
		Plt_Button($but_wfpc2_2_x_vst,
			   $but_wfpc2_2_x_vsp,
			   $but_wfpc2_2_y_vst,
			   $but_wfpc2_2_y_vsp,
			   $but_wfpc2_2_lab,
			   $but_wfpc2_2_sta);
	    }
	}
	# WFPC2 button 3.
	if ($x > $but_wfpc2_3_x_vst and $x < $but_wfpc2_3_x_vsp and
            $y > $but_wfpc2_3_y_vst and $y < $but_wfpc2_3_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($but_wfpc2_3_sta == 0) {
		$but_wfpc2_3_sta = 1;
		Plt_Button($but_wfpc2_3_x_vst,
			   $but_wfpc2_3_x_vsp,
			   $but_wfpc2_3_y_vst,
			   $but_wfpc2_3_y_vsp,
			   $but_wfpc2_3_lab,
			   $but_wfpc2_3_sta);
		pgbbuf;
		$ima_wfpc2_x_off = 0;
		$ima_wfpc2_y_off = 0;
		Plt_WFPC2($fil,$ra,$dec);
		pgebuf;
		$but_wfpc2_3_sta = 0;
		Plt_Button($but_wfpc2_3_x_vst,
			   $but_wfpc2_3_x_vsp,
			   $but_wfpc2_3_y_vst,
			   $but_wfpc2_3_y_vsp,
			   $but_wfpc2_3_lab,
			   $but_wfpc2_3_sta);
	    }
	}
	# WFPC2 button 4.
	if ($x > $but_wfpc2_4_x_vst and $x < $but_wfpc2_4_x_vsp and
            $y > $but_wfpc2_4_y_vst and $y < $but_wfpc2_4_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($but_wfpc2_4_sta == 0) {
		$but_wfpc2_4_sta = 1;
		Plt_Button($but_wfpc2_4_x_vst,
			   $but_wfpc2_4_x_vsp,
			   $but_wfpc2_4_y_vst,
			   $but_wfpc2_4_y_vsp,
			   $but_wfpc2_4_lab,
			   $but_wfpc2_4_sta);
		print "Enter minimum value [$ima_wfpc2_min]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_wfpc2_min = $tmp;
		}
		print "Enter maximum value [$ima_wfpc2_max]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_wfpc2_max = $tmp;
		}
		pgbbuf;
		Plt_WFPC2($fil,$ra,$dec);
		pgebuf;
		$but_wfpc2_4_sta = 0;
		Plt_Button($but_wfpc2_4_x_vst,
			   $but_wfpc2_4_x_vsp,
			   $but_wfpc2_4_y_vst,
			   $but_wfpc2_4_y_vsp,
			   $but_wfpc2_4_lab,
			   $but_wfpc2_4_sta);
	    }
	}
	# WFPC2 button 5.
	if ($x > $but_wfpc2_5_x_vst and $x < $but_wfpc2_5_x_vsp and
            $y > $but_wfpc2_5_y_vst and $y < $but_wfpc2_5_y_vsp) {
	    if (! $dat_wfpc2_got) {next;}
	    if ($but_wfpc2_5_sta == 0) {
		$but_wfpc2_5_sta = 1;
		Plt_Button($but_wfpc2_5_x_vst,
			   $but_wfpc2_5_x_vsp,
			   $but_wfpc2_5_y_vst,
			   $but_wfpc2_5_y_vsp,
			   $but_wfpc2_5_lab,
			   $but_wfpc2_5_sta);
		pgbbuf;
		$col_tab = 1;
		$col_con = 0.1;
		$col_bri = 0.5;
		Color_Table($col_tab,$col_con,$col_bri);
		$ima_wfpc2_x_off = 0;
		$ima_wfpc2_y_off = 0;
		$ima_wfpc2_x_zoom = 1;
		$ima_wfpc2_y_zoom = 1;
		$ima_wfpc2_min = $dat_wfpc2_min;
		$ima_wfpc2_max = $dat_wfpc2_max;
		Plt_WFPC2($fil,$ra,$dec);
		$but_wfpc2_5_sta = 0;
		pgebuf;
		Plt_Button($but_wfpc2_5_x_vst,
			   $but_wfpc2_5_x_vsp,
			   $but_wfpc2_5_y_vst,
			   $but_wfpc2_5_y_vsp,
			   $but_wfpc2_5_lab,
			   $but_wfpc2_5_sta);
	    }
	}
	# NICMOS image.
	if ($x > $ima_nicmos_x_vst and $x < $ima_nicmos_x_vsp and
            $y > $ima_nicmos_y_vst and $y < $ima_nicmos_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($key eq "A") {
                # Recenter display.
		$ima_nicmos_x_off = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst)-$ima_nicmos_x_cen;
		$ima_nicmos_y_off = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst)-$ima_nicmos_y_cen;
		pgbbuf;
		Plt_NICMOS($fil,$ra,$dec);
		pgebuf;
	    } elsif ($key eq "X") {
                # Print RA and Dec.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
		    XY2RaDec_CD($px,$py,$dat_nicmos_hdr);
		print "                $rh:$rm:$rs $dc$dd:$dm:$ds";
		if ($px < 0 or $px > $dat_nicmos_nx or
                    $py < 0 or $py > $dat_nicmos_ny) {
		    print "\n";
		} else {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_nicmos_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "  $px $py $val\n";
		}
	    } elsif ($key eq "D") {
                # Change display center coordinate.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		if ($px > 0 and $px < $dat_nicmos_nx or
                    $py > 0 and $py < $dat_nicmos_ny) {
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_nicmos_hdr);
		    $ra = "$rh:$rm:$rs";
		    $dec = "$dc$dd:$dm:$ds";
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_nicmos_data->[$py][$px];
		    $px += 1;
		    $py += 1;
		    $px = sprintf("%3.0d",$px);
		    $py = sprintf("%3.0d",$py);
		    print "                $ra $dec  $px $py $val\n";
		    # Replot display.
		    $ima_dss2_x_off = 0;
		    $ima_dss2_y_off = 0;
		    $ima_2mass_x_off = 0;
		    $ima_2mass_y_off = 0;
		    $ima_wfpc2_x_off = 0;
		    $ima_wfpc2_y_off = 0;
		    $ima_nicmos_x_off = 0;
		    $ima_nicmos_y_off = 0;
		    pgbbuf;
		    Plt_Title($obj,$ra,$dec);
		    Plt_DSS2_R($fil,$ra,$dec);
		    Plt_2MASS_K($fil,$ra,$dec);
		    Plt_WFPC2($fil,$ra,$dec);
		    Plt_NICMOS($fil,$ra,$dec);
		    pgsvp(0,1,0,1);
		    pgswin(0,1,0,1);
		    pgebuf;
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "s") {
                # Set sky value.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		if ($px > 0 and $px < $dat_nicmos_nx or
                    $py > 0 and $py < $dat_nicmos_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $ima_nicmos_sky = $dat_nicmos_data->[$py][$px];
		    print "Sky value = $ima_nicmos_sky\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "m") {
                # Report magnitude.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		if ($px > 0 and $px < $dat_nicmos_nx or
                    $py > 0 and $py < $dat_nicmos_ny) {
		    $px = int($px+0.5)-1;
		    $py = int($py+0.5)-1;
		    $val = $dat_nicmos_data->[$py][$px];
		    $cam = substr($dat_nicmos_hdr->{'APERTURE'},1,4); 
		    $val = ($val-$ima_nicmos_sky)*$dat_nicmos_hdr->{'PHOTFNU'};
		    $wav = $dat_nicmos_hdr->{'PHOTPLAM'}/10000.0;
		    $f0 = 5513.15/$wav**3/(exp(1.2848/$wav)-1.0);
		    $val = -2.5*log10($val/$f0);
		    if ($cam eq "NIC1") {
			$val += 6.833;
		    } elsif ($cam eq "NIC2") {
			$val += 5.625;
		    } elsif ($cam eq "NIC3") {
			$val += 3.495;
		    } else {
			die "GS_SEARCH.PL: Invalid NICMOS camera $cam.\n";
		    }
		    $val = sprintf("%6.3f",$val);
		    print "Surface brightness = $val magnitudes/pixel.\n";
		    if ($cam eq "NIC1") {
			$val -= 6.833;
		    } elsif ($cam eq "NIC2") {
			$val -= 5.625;
		    } elsif ($cam eq "NIC3") {
			$val -= 3.495;
		    } else {
			die "GS_SEARCH.PL: Invalid NICMOS camera $cam.\n";
		    }
		    $val = sprintf("%6.3f",$val);
		    print "                   = $val magnitudes/arcsec^2.\n";
		    $val += 3.495;
		    $val = sprintf("%6.3f",$val);
		    print "                   = $val magnitudes/0.2\"x0.2\".\n";
		} else {
		    print "GS_SEARCH.PL: Coordinate is outside image!\n";
		}
	    } elsif ($key eq "a") {
                # Mark AOWFS star.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		if ($px > 0 and $px < $dat_nicmos_nx or
                    $py > 0 and $py < $dat_nicmos_ny) {
		    # Get AOWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_nicmos_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_aowfs_ra and
			$new_dec ne $dat_aowfs_dec) {
			$dat_aowfs_got = 1;
			$dat_aowfs_ra = $new_ra;
			$dat_aowfs_dec = $new_dec;
		    } else {
			$dat_aowfs_got = 0;
			$dat_aowfs_ra = -100;
			$dat_aowfs_dec = -100;
		    }
		} else {
		    $dat_aowfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "o") {
                # Mark OIWFS star.
		$px = $ima_nicmos_x_wst+($x-$ima_nicmos_x_vst)/
		    ($ima_nicmos_x_vsp-$ima_nicmos_x_vst)*
		    ($ima_nicmos_x_wsp-$ima_nicmos_x_wst);
		$py = $ima_nicmos_y_wst+($y-$ima_nicmos_y_vst)/
		    ($ima_nicmos_y_vsp-$ima_nicmos_y_vst)*
		    ($ima_nicmos_y_wsp-$ima_nicmos_y_wst);
		if ($px > 0 and $px < $dat_nicmos_nx or
                    $py > 0 and $py < $dat_nicmos_ny) {
		    # Get OIWFS star RA and Dec.
		    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = 
			XY2RaDec_CD($px,$py,$dat_nicmos_hdr);
		    $new_ra = "$rh:$rm:$rs";
		    $new_dec = "$dc$dd:$dm:$ds";
		    if ($new_ra  ne $dat_oiwfs_ra and
			$new_dec ne $dat_oiwfs_dec) {
			$dat_oiwfs_got = 1;
			$dat_oiwfs_ra = $new_ra;
			$dat_oiwfs_dec = $new_dec;
		    } else {
			$dat_oiwfs_got = 0;
			$dat_oiwfs_ra = -100;
			$dat_oiwfs_dec = -100;
		    }
		} else {
		    $dat_oiwfs_got = 0;
		}
		# Replot display.
		pgbbuf;
		Plt_DSS2_R($fil,$ra,$dec);
		Plt_2MASS_K($fil,$ra,$dec);
		Plt_WFPC2($fil,$ra,$dec);
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } elsif ($key eq "g") {
                # Draw FOV grid.
		if ($ima_nicmos_grid) {
		    $ima_nicmos_grid = 0;
		} else {
		    $ima_nicmos_grid = 1;
		}
		# Replot display.
		pgbbuf;
		Plt_NICMOS($fil,$ra,$dec);
		pgsvp(0,1,0,1);
		pgswin(0,1,0,1);
		pgebuf;
	    } else {
		print "$key\n";
	    }
	}
	# NICMOS button 1.
	if ($x > $but_nicmos_1_x_vst and $x < $but_nicmos_1_x_vsp and
            $y > $but_nicmos_1_y_vst and $y < $but_nicmos_1_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($but_nicmos_1_sta == 0) {
		$but_nicmos_1_sta = 1;
		Plt_Button($but_nicmos_1_x_vst,
			   $but_nicmos_1_x_vsp,
			   $but_nicmos_1_y_vst,
			   $but_nicmos_1_y_vsp,
			   $but_nicmos_1_lab,
			   $but_nicmos_1_sta);
		pgbbuf;
		$ima_nicmos_x_zoom *= 2;
		$ima_nicmos_y_zoom *= 2;
		Plt_NICMOS($fil,$ra,$dec);
		$but_nicmos_1_sta = 0;
		pgebuf;
		Plt_Button($but_nicmos_1_x_vst,
			   $but_nicmos_1_x_vsp,
			   $but_nicmos_1_y_vst,
			   $but_nicmos_1_y_vsp,
			   $but_nicmos_1_lab,
			   $but_nicmos_1_sta);
	    }
	}
	# NICMOS button 2.
	if ($x > $but_nicmos_2_x_vst and $x < $but_nicmos_2_x_vsp and
            $y > $but_nicmos_2_y_vst and $y < $but_nicmos_2_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($but_nicmos_2_sta == 0) {
		$but_nicmos_2_sta = 1;
		Plt_Button($but_nicmos_2_x_vst,
			   $but_nicmos_2_x_vsp,
			   $but_nicmos_2_y_vst,
			   $but_nicmos_2_y_vsp,
			   $but_nicmos_2_lab,
			   $but_nicmos_2_sta);
		pgbbuf;
		$ima_nicmos_x_zoom /= 2;
		$ima_nicmos_y_zoom /= 2;
		Plt_NICMOS($fil,$ra,$dec);
		$but_nicmos_2_sta = 0;
		pgebuf;
		Plt_Button($but_nicmos_2_x_vst,
			   $but_nicmos_2_x_vsp,
			   $but_nicmos_2_y_vst,
			   $but_nicmos_2_y_vsp,
			   $but_nicmos_2_lab,
			   $but_nicmos_2_sta);
	    }
	}
	# NICMOS button 3.
	if ($x > $but_nicmos_3_x_vst and $x < $but_nicmos_3_x_vsp and
            $y > $but_nicmos_3_y_vst and $y < $but_nicmos_3_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($but_nicmos_3_sta == 0) {
		$but_nicmos_3_sta = 1;
		Plt_Button($but_nicmos_3_x_vst,
			   $but_nicmos_3_x_vsp,
			   $but_nicmos_3_y_vst,
			   $but_nicmos_3_y_vsp,
			   $but_nicmos_3_lab,
			   $but_nicmos_3_sta);
		pgbbuf;
		$ima_nicmos_x_off = 0;
		$ima_nicmos_y_off = 0;
		Plt_NICMOS($fil,$ra,$dec);
		pgebuf;
		$but_nicmos_3_sta = 0;
		Plt_Button($but_nicmos_3_x_vst,
			   $but_nicmos_3_x_vsp,
			   $but_nicmos_3_y_vst,
			   $but_nicmos_3_y_vsp,
			   $but_nicmos_3_lab,
			   $but_nicmos_3_sta);
	    }
	}
	# NICMOS button 4.
	if ($x > $but_nicmos_4_x_vst and $x < $but_nicmos_4_x_vsp and
            $y > $but_nicmos_4_y_vst and $y < $but_nicmos_4_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($but_nicmos_4_sta == 0) {
		$but_nicmos_4_sta = 1;
		Plt_Button($but_nicmos_4_x_vst,
			   $but_nicmos_4_x_vsp,
			   $but_nicmos_4_y_vst,
			   $but_nicmos_4_y_vsp,
			   $but_nicmos_4_lab,
			   $but_nicmos_4_sta);
		print "Enter minimum value [$ima_nicmos_min]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_nicmos_min = $tmp;
		}
		print "Enter maximum value [$ima_nicmos_max]: ";
		$tmp = <STDIN>;
		if ($tmp ne "\n") {
		    chomp $tmp;
		    $ima_nicmos_max = $tmp;
		}
		pgbbuf;
		Plt_NICMOS($fil,$ra,$dec);
		pgebuf;
		$but_nicmos_4_sta = 0;
		Plt_Button($but_nicmos_4_x_vst,
			   $but_nicmos_4_x_vsp,
			   $but_nicmos_4_y_vst,
			   $but_nicmos_4_y_vsp,
			   $but_nicmos_4_lab,
			   $but_nicmos_4_sta);
	    }
	}
	# NICMOS button 5.
	if ($x > $but_nicmos_5_x_vst and $x < $but_nicmos_5_x_vsp and
            $y > $but_nicmos_5_y_vst and $y < $but_nicmos_5_y_vsp) {
	    if (! $dat_nicmos_got) {next;}
	    if ($but_nicmos_5_sta == 0) {
		$but_nicmos_5_sta = 1;
		Plt_Button($but_nicmos_5_x_vst,
			   $but_nicmos_5_x_vsp,
			   $but_nicmos_5_y_vst,
			   $but_nicmos_5_y_vsp,
			   $but_nicmos_5_lab,
			   $but_nicmos_5_sta);
		pgbbuf;
		$col_tab = 1;
		$col_con = 0.1;
		$col_bri = 0.5;
		Color_Table($col_tab,$col_con,$col_bri);
		$ima_nicmos_x_off = 0;
		$ima_nicmos_y_off = 0;
		$ima_nicmos_x_zoom = 1;
		$ima_nicmos_y_zoom = 1;
		$ima_nicmos_min = $dat_nicmos_min;
		$ima_nicmos_max = $dat_nicmos_max;
		Plt_NICMOS($fil,$ra,$dec);
		$but_nicmos_5_sta = 0;
		pgebuf;
		Plt_Button($but_nicmos_5_x_vst,
			   $but_nicmos_5_x_vsp,
			   $but_nicmos_5_y_vst,
			   $but_nicmos_5_y_vsp,
			   $but_nicmos_5_lab,
			   $but_nicmos_5_sta);
	    }
	}
	pgcurs($x,$y,$key);
    }
    $but_title_3_sta = 0;
    Plt_Button($but_title_3_x_vst,
	       $but_title_3_x_vsp,
	       $but_title_3_y_vst,
	       $but_title_3_y_vsp,
	       $but_title_3_lab,
	       $but_title_3_sta);
    return;
}

# Routine to draw a circle.

sub Plt_Circle {
    my ($x0,$y0,$rad) = @_;
    my ($i,$x,$y);
    $x = $x0;
    $y = $y0+$rad;
    pgmove($x,$y);
    foreach $i (0..360) {
	$x = $x0+$rad*sin($i/180.0*3.1415925);
	$y = $y0+$rad*cos($i/180.0*3.1415925);
	pgdraw($x,$y);
    }
    return;
}

sub Plt_Button {
    my ($xst,$xsp,$yst,$ysp,$label,$mode) = @_;
    my ($vx1,$vx2,$vy1,$vy2);
    my ($wx1,$wx2,$wy1,$wy2);
    # Save current viewport and window.
    pgqvp(0,$vx1,$vx2,$vy1,$vy2);
    pgqwin($wx1,$wx2,$wy1,$wy2);
    # Set viewport and window.
    pgsvp($xst,$xsp,$yst,$ysp);
    pgswin(0,1,0,1);
    # Plot button.
    pgsch(1);
    if ($mode == 0) {
	pgsci(10);
	pgsfs(1);
	pgrect(0,1,0,1);
	pgsci(1);
	pgsfs(2);
	pgrect(0,1,0,1);
	pgptxt(0.5,0.3,0.0,0.5,$label);
    } else {
	pgsci(1);
	pgsfs(1);
	pgrect(0,1,0,1);
	pgsci(10);
	pgptxt(0.5,0.3,0.0,0.5,$label);
    }
    pgsci(1);
    pgsfs(1);
    pgsch(1);
    # Reset viewport and window.
    pgsvp($vx1,$vx2,$vy1,$vy2);
    pgswin($wx1,$wx2,$wy1,$wy2);
    return;
}

# Routine to mark USNO stars on image.

sub Mark_USNO {
    my ($coord,$size,$header) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    $rh = substr($coord, 0,2);
    $rm = substr($coord, 3,2);
    $rs = substr($coord, 6,5);
    $dc = substr($coord,12,1);
    $dd = substr($coord,13,2);
    $dm = substr($coord,16,2);
    $ds = substr($coord,19,4);
    ($x,$y) = RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$header);
    pgsci(8);
    pgslw(2);
    pgmove($x-$size,$y-$size);
    pgdraw($x+$size,$y-$size);
    pgdraw($x+$size,$y+$size);
    pgdraw($x-$size,$y+$size);
    pgdraw($x-$size,$y-$size);
    pgsci(1);
    pgslw(1);
    return;
}

# Routine to mark AOWFS star on image.

sub Mark_AOWFS {
    my ($coord,$size,$header) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    $rh = substr($coord, 0,2);
    $rm = substr($coord, 3,2);
    $rs = substr($coord, 6,5);
    $dc = substr($coord,12,1);
    $dd = substr($coord,13,2);
    $dm = substr($coord,16,2);
    $ds = substr($coord,19,4);
    ($x,$y) = RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$header);
    pgsci(3);
    pgslw(2);
    pgmove($x-$size/2.0,$y-0.289*$size);
    pgdraw($x+$size/2.0,$y-0.289*$size);
    pgdraw($x,$y+$size/1.732);
    pgdraw($x-$size/2.0,$y-0.289*$size);
    pgsci(1);
    pgslw(1);
    return;
}

# Routine to mark OIWFS star on image.

sub Mark_OIWFS {
    my ($coord,$size,$header) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$x,$y);
    $rh = substr($coord, 0,2);
    $rm = substr($coord, 3,2);
    $rs = substr($coord, 6,5);
    $dc = substr($coord,12,1);
    $dd = substr($coord,13,2);
    $dm = substr($coord,16,2);
    $ds = substr($coord,19,4);
    ($x,$y) = RaDec2XY_CD($rh,$rm,$rs,$dc,$dd,$dm,$ds,$header);
    pgsci(3);
    pgslw(2);
    Plt_Circle($x,$y,$size/2.0);
    pgsci(1);
    pgslw(1);
    return;
}

# Routine to read a FITS format file.

sub Read_FITS {
    my ($file) = @_;
    my ($array,$naxis1,$naxis2,$header);
    my ($fptr, $naxes, $anynul);
    my ($min) = 1;
    my ($max) = 0;
    my ($status) = 0;
    # Open FITS file.
    $fptr = CFITSIO::open_file($file,CFITSIO::READONLY(),$status);
    Check_Status($status) or return (0,$array,$naxis1,$naxis2,$header,$min,$max);
    # Read image dimensions.
    $fptr->get_img_parm(undef,undef,$naxes,$status);
    Check_Status($status) or return (0,$array,$naxis1,$naxis2,$header,$min,$max);
    ($naxis1,$naxis2) = @{$naxes};
    # Read data array.
    $fptr->read_2d_lng(1,0,$naxis1,$naxis1,$naxis2,$array,$anynul,$status);
    Check_Status($status) or return (0,$array,$naxis1,$naxis2,$header,$min,$max);
    # Read header key/value to a hash.
    ($header,$status) = $fptr->read_header;
    Check_Status($status) or return (0,$array,$naxis1,$naxis2,$header,$min,$max);
    # Close FITS file.
    $fptr->close_file($status);
    Check_Status($status) or return (0,$array,$naxis1,$naxis2,$header,$min,$max);
    ($min,$max) = MinMax($array,$naxis1,$naxis1);
#    print "Size of FITS array $#$array\n";
    return (1,$array,$naxis1,$naxis2,$header,$min,$max);
}

# Routine to check CFITSIO status.

sub Check_Status {
    my ($status) = shift;
    my ($error);
    if ($status != 0) {
	return 0;
    }
    return 1;
}

# Routine to return the minimum and maximum data value.

sub MinMax {
    my ($array,$nx,$ny) = @_;
    my ($val, $mean, $sigma);
    my ($n) = 0;
    my ($sum) = 0;
    my ($sumsq) = 0;
    my ($min) = +1.e+30;
    my ($max) = -1.e+30;

    foreach my $i (0..$nx-1) {
	foreach my $j (0..$ny-1) {
	    if (defined($array->[$j][$i])) {
		$val = $array->[$j][$i];
		$n += 1;
		$sum += $val;
		$sumsq += $val*$val;
		if ($val < $min) {$min = $val;}
		if ($val > $max) {$max = $val;}
	    }
	}
    }

    if ($n > 2) {
	$mean = $sum/$n;
	$sigma = sqrt(($sumsq-$n*$mean**2)/($n-1));
	$min = $mean-5*$sigma;
	$val = $mean+10*$sigma;
	if ($val < $max) {$max = $val;}
    }
    return ($min,$max);
}

# Routine to convert pixel number to RA and Dec using FITS CD matrix.

sub XY2RaDec_CD {
    my ($x,$y,$header) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
    my ($cd1_1, $cd1_2, $cd2_1, $cd2_2);
    my ($cdelt1, $cdelt2, $crota1, $crota2);
    my ($ra, $dec);
    my ($pi) = 3.14159265359;
    # Get CD matrix elements.
    # Get CD matrix elements.
    if (defined ($header->{'CD1_1'}) and 
        defined ($header->{'CD2_2'})) {
	$cd1_1 = $header->{'CD1_1'};
	$cd2_2 = $header->{'CD2_2'};
	if (defined ($header->{'CD1_2'})) {
	    $cd1_2 = $header->{'CD1_2'};
	} else {
	    $cd1_2 = 0.0;
	}
	if (defined ($header->{'CD2_1'})) {
	    $cd2_1 = $header->{'CD2_1'};
	} else {
	    $cd2_1 = 0.0;
	}
    } elsif (defined ($header->{'CDELT1'}) and
	     defined ($header->{'CDELT2'})) {
	$cdelt1 = $header->{'CDELT1'};
	$cdelt2 = $header->{'CDELT2'};
	if (defined ($header->{'CROTA1'})) {
	    $crota1 = $header->{'CROTA1'};
	} else {
	    $crota1 = 0.0;
	}
	if (defined ($header->{'CROTA2'})) {
	    $crota2 = $header->{'CROTA2'};
	} else {
	    $crota2 = 0.0;
	}
	$cd1_1 = $cdelt1*cos($crota2*$pi/180);
	$cd1_2 = -$cdelt2*sin($crota2*$pi/180);
	$cd2_1 = $cdelt1*sin($crota2*$pi/180);
	$cd2_2 = $cdelt2*cos($crota2*$pi/180);
    } else {
	print "GS_SEARCH.PL: Cannot access WCS information!\n";
	$rh = 0; $rm = 0; $rs = 0;
	$dc = '-'; $dd = 0; $dm = 0; $ds = 0;
	return ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
    }
    # Convert to pixel coordinates relative to the reference pixel.
    $x -= $header->{'CRPIX1'};
    $y -= $header->{'CRPIX2'};
    # Use CD matrix to convert to RA and Dec offsets in degrees.
    if (substr($header->{'CTYPE1'},1,4) eq "RA--") {
	$ra  = $cd1_1*$x+$cd1_2*$y;
	$dec = $cd2_1*$x+$cd2_2*$y;
    } else {
	$ra  = $cd2_1*$x+$cd2_2*$y;
	$dec = $cd1_1*$x+$cd1_2*$y;
    }
    # Convert to absolute RA and Dec.
    if (substr($header->{'CTYPE1'},1,4) eq "RA--") {
	$dec += $header->{'CRVAL2'};
	$ra  /= cos($dec*$pi/180);
	$ra  += $header->{'CRVAL1'};
    } else {
	$dec += $header->{'CRVAL1'};
	$ra  /= cos($dec*$pi/180);
	$ra  += $header->{'CRVAL2'};
    }
    # Convert RA and Dec from degrees to hms.
    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = Deg2HMS($ra,$dec);
    $rh = sprintf ("%02.0d",$rh);
    $rm = sprintf ("%02.0d",$rm);
    $rs = sprintf ("%05.2f",$rs);
    $dd = sprintf ("%02.0d",$dd);
    $dm = sprintf ("%02.0d",$dm);
    $ds = sprintf ("%04.1f",$ds);
    return ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
}

# Routine to convert RA and Dec to pixel number using FITS CD matrix.

sub RaDec2XY_CD {
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$header) = @_;
    my ($x,$y);
    my ($cd1_1, $cd1_2, $cd2_1, $cd2_2);
    my ($iv1_1, $iv1_2, $iv2_1, $iv2_2);
    my ($cdelt1, $cdelt2, $crota1, $crota2);
    my ($ra, $dec, $det);
    my ($pi) = 3.14159265359;
    # Get CD matrix elements.
    if (defined ($header->{'CD1_1'}) and 
        defined ($header->{'CD2_2'})) {
	$cd1_1 = $header->{'CD1_1'};
	$cd2_2 = $header->{'CD2_2'};
	if (defined ($header->{'CD1_2'})) {
	    $cd1_2 = $header->{'CD1_2'};
	} else {
	    $cd1_2 = 0.0;
	}
	if (defined ($header->{'CD2_1'})) {
	    $cd2_1 = $header->{'CD2_1'};
	} else {
	    $cd2_1 = 0.0;
	}
    } elsif (defined ($header->{'CDELT1'}) and
	     defined ($header->{'CDELT2'})) {
	$cdelt1 = $header->{'CDELT1'};
	$cdelt2 = $header->{'CDELT2'};
	if (defined ($header->{'CROTA1'})) {
	    $crota1 = $header->{'CROTA1'};
	} else {
	    $crota1 = 0.0;
	}
	if (defined ($header->{'CROTA2'})) {
	    $crota2 = $header->{'CROTA2'};
	} else {
	    $crota2 = 0.0;
	}
	$cd1_1 = $cdelt1*cos($crota2*$pi/180);
	$cd1_2 = -$cdelt2*sin($crota2*$pi/180);
	$cd2_1 = $cdelt1*sin($crota2*$pi/180);
	$cd2_2 = $cdelt2*cos($crota2*$pi/180);
    } else {
	print "GS_SEARCH.PL: Cannot access WCS information!\n";
	$x = 0; $y = 0;
	return ($x,$y);
    }
    # Form inverse of CD matrix.
    $det = $cd1_1*$cd2_2-$cd1_2*$cd2_1;
    $iv1_1 = $cd2_2/$det;
    $iv1_2 = -$cd1_2/$det;
    $iv2_1 = -$cd2_1/$det;
    $iv2_2 = $cd1_1/$det;
    # Convert RA and Dec to degrees.
    $ra = $rh+$rm/60+$rs/3600;
    $ra *= 15;
    if ($ra >= 360) {$ra -= 360}
    $dec = $dd+$dm/60+$ds/3600;
    if ($dc eq "-") {$dec *= -1;}
    # Convert to RA and Dec relative to the reference pixel.
    if (substr($header->{'CTYPE1'},1,4) eq "RA--") {
	$ra  -= $header->{'CRVAL1'};
	$ra  *= cos($dec*$pi/180);
	$dec -= $header->{'CRVAL2'};
    } else {
	$ra  -= $header->{'CRVAL2'};
	$ra  *= cos($dec*$pi/180);
	$dec -= $header->{'CRVAL1'};
    }
    # Use IV matrix to convert to X,Y pixel offsets.
    if (substr($header->{'CTYPE1'},1,4) eq "RA--") {
	$x = $iv1_1*$ra+$iv1_2*$dec;
	$y = $iv2_1*$ra+$iv2_2*$dec;
    } else {
	$x = $iv1_1*$dec+$iv1_2*$ra;
	$y = $iv2_1*$dec+$iv2_2*$ra;
    }
    # Convert to absolute pixel coordinates.
    $x += $header->{'CRPIX1'};
    $y += $header->{'CRPIX2'};
    return ($x,$y);
}

# Routine to convert pixel number on a DSS-2 FITS image to RA and Dec.

sub XY2RaDec_DSS {
    my ($x,$y,$header) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
    my ($arcsec_per_radian) = 206264.80625;
    my ($pi) = 3.14159265359;
    # Convert to DSS pixel coordinates relative to the plate center.
    my ($ox) = $x+$header->{'CNPIX1'}+0.5;
    my ($oy) = $y+$header->{'CNPIX2'}+0.5;
    # Convert from pixels to mm from plate center.
    $ox = ($header->{'PPO3'}-$ox*$header->{'XPIXELSZ'})/1000;
    $oy = ($oy*$header->{'YPIXELSZ'}-$header->{'PPO6'})/1000;
    my ($ox2) = $ox*$ox;
    my ($oy2) = $oy*$oy;
    my ($ox3) = $ox*$ox2;
    my ($oy3) = $oy*$oy2;
    # Compute standard coordinates, xi and eta in arcsec, from X,Y and 
    # plate model.
    my ($obj_xi) = 
	$header->{'AMDX1' }*$ox             + 
        $header->{'AMDX2' }*$oy             +
	$header->{'AMDX3' }                 +
	$header->{'AMDX4' }*$ox2            +
	$header->{'AMDX5' }*$ox*$oy         +
        $header->{'AMDX6' }*$oy2            +
        $header->{'AMDX7' }*($ox2+$oy2)     +
        $header->{'AMDX8' }*$ox3            +
        $header->{'AMDX9' }*$ox2*$oy        +
        $header->{'AMDX10'}*$ox*$oy2        +
        $header->{'AMDX11'}*$oy3            +
        $header->{'AMDX12'}*$ox*($ox2+$oy2) +
        $header->{'AMDX13'}*$ox*($ox2+$oy2)*($ox2*$oy2);
    my ($obj_eta) = 
	$header->{'AMDY1' }*$oy             + 
        $header->{'AMDY2' }*$ox             +
	$header->{'AMDY3' }                 +
	$header->{'AMDY4' }*$oy2            +
	$header->{'AMDY5' }*$oy*$ox         +
        $header->{'AMDY6' }*$ox2            +
        $header->{'AMDY7' }*($oy2+$ox2)     +
        $header->{'AMDY8' }*$oy3            +
        $header->{'AMDY9' }*$oy2*$ox        +
        $header->{'AMDY10'}*$oy*$ox2        +
        $header->{'AMDY11'}*$ox3            +
        $header->{'AMDY12'}*$oy*($oy2+$ox2) +
        $header->{'AMDY13'}*$oy*($oy2+$ox2)*($oy2*$ox2);
    # Convert xi and eta to radians.
    $obj_xi  /= $arcsec_per_radian;
    $obj_eta /= $arcsec_per_radian;
    # Convert plate center RA and Dec to radians.
    my ($rac_rad) = $header->{'PLTRAH'}+
                    $header->{'PLTRAM'}/60+
      	            $header->{'PLTRAS'}/3600;
    $rac_rad *= $pi/12;
    if ($rac_rad > $pi) {$rac_rad -= 2*$pi;}
    my ($decc_rad) = $header->{'PLTDECD'}+
                     $header->{'PLTDECM'}/60+
		     $header->{'PLTDECS'}/3600;
    if ($header->{'PLTDECSN'} eq "-") {$decc_rad *= -1};
    $decc_rad *= $pi/180;
    # Convert standard coordinates to RA and Dec.
    my ($num) = $obj_xi/cos($decc_rad);
    my ($den) = 1-$obj_eta*tan($decc_rad);
    my ($ra) = atan2($num,$den)+$rac_rad;
    if ($ra < 0) {$ra += 2*$pi;}
    $num = cos($ra-$rac_rad);
    $den = (1-$obj_eta*tan($decc_rad))/($obj_eta+tan($decc_rad));
    my $dec = atan($num,$den);
    # Convert RA and Dec from radians to hms.
    ($rh,$rm,$rs,$dc,$dd,$dm,$ds) = Rad2HMS($ra,$dec);
    return ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
}

# Routine to convert RA and Dec to pixel number on a DSS-2 FITS image.

sub RaDec2XY_DSS {
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds,$header) = @_;
    my ($x,$y);
    my ($max_iter) = 50;
    my ($tol) = 5e-7;
    my ($arcsec_per_radian) = 206264.80625;
    my ($pi) = 3.14159265359;
    # Convert RA and Dec to radians.
    my ($ra_rad) = $rh+$rm/60+$rs/3600;
    $ra_rad *= $pi/12;
    if ($ra_rad > $pi) {$ra_rad -= 2*$pi;}
    my ($dec_rad) = $dd+$dm/60+$ds/3600;
    if ($dc eq "-") {$dec_rad *= -1;}
    $dec_rad *= $pi/180;
    my ($rac_rad) = $header->{'PLTRAH'}+
                    $header->{'PLTRAM'}/60+
      	            $header->{'PLTRAS'}/3600;
    $rac_rad *= $pi/12;
    if ($rac_rad > $pi) {$rac_rad -= 2*$pi;}
    my ($decc_rad) = $header->{'PLTDECD'}+
                     $header->{'PLTDECM'}/60+
		     $header->{'PLTDECS'}/3600;
    if ($header->{'PLTDECSN'} eq "-") {$decc_rad *= -1};
    $decc_rad *= $pi/180;
    # Initialize.
    my ($i) = 0;
    my ($delta_x) = 2*$tol;
    my ($delta_y) = 2*$tol;
    # Convert RA and Dec to standard coordinates, xi and eta, in arcsec.
    my ($div) = sin($dec_rad)*sin($decc_rad)+cos($dec_rad)*cos($decc_rad)*
	cos($ra_rad-$rac_rad);
    my ($xi) = cos($dec_rad)*sin($ra_rad-$rac_rad)*$arcsec_per_radian/$div;
    my ($eta) = (sin($dec_rad)*cos($decc_rad)-cos($dec_rad)*sin($decc_rad)*
	cos($ra_rad-$rac_rad))*$arcsec_per_radian/$div;
    # Set initail value for x,y.
    my ($obj_x) = $xi/$header->{'PLTSCALE'};
    my ($obj_y) = $eta/$header->{'PLTSCALE'};
    # Iterate by Newton's method.
    while (($i < $max_iter) and 
           (abs($delta_x) >= $tol) and
           (abs($delta_y) >= $tol)) {
	$i += 1;
    	my ($f,$fx,$fy,$g,$gx,$gy) = PltModel($obj_x,$obj_y,$header);
	$f -= $xi;
	$g -= $eta;
	$delta_x = (-$f*$gy+$g*$fy)/($fx*$gy-$fy*$gx);
	$delta_y = (-$g*$fx+$f*$gx)/($fx*$gy-$fy*$gx);
	$obj_x += $delta_x;
	$obj_y += $delta_y;
    }
    # Convert mm from plate center to pixels.
    $x = ($header->{'PPO3'}-$obj_x*1000)/$header->{'XPIXELSZ'};
    $y = ($header->{'PPO6'}+$obj_y*1000)/$header->{'YPIXELSZ'};
    # Convert to pixels on the FITS image.
    #  NOTE: We need to subtract 0.5 pixel to allow for the DSS pixel 
    #        origin definition (DSS coordinates refer to the lower left 
    #        corner of the pixel; PGPLOT coordinates refer to the pixel 
    #        center).
    $x -= $header->{'CNPIX1'}+0.5;
    $y -= $header->{'CNPIX2'}+0.5;
    return ($x,$y);
}

# Routine to compute the plate model and its partial derivatives for use
# in computing inverse astrometric solutions. Based on PLTMODEL in the 
# GetImage software (/pkg/merlin/dss/getimage1.2/src/astrmcal.c).

sub PltModel {
    my ($x,$y,$header) = @_;
    my ($f,$fx,$fy,$g,$gx,$gy);
    # f  is the xi standard coordinate.
    # fx is the derivative of xi with respect to x.
    # fy is the derivative of xi with respect to y.
    # g  is the eta standard coordinate.
    # gx is the derivative of eta with respect to x.
    # gy is the derivative of eta with respect to y.
    my ($cjunk,$x4,$y4);
    # X plate model.
    $cjunk = ($x*$x+$y*$y)*($x*$x+$y*$y);
    $x4 = ($x*$x)*($x*$x);
    $y4 = ($y*$y)*($y*$y);
    $f =  $header->{'AMDX1' }*$x               +
          $header->{'AMDX2' }*$y               +
	  $header->{'AMDX3' }                  +
          $header->{'AMDX4' }*$x*$x            +
          $header->{'AMDX5' }*$x*$y            +
          $header->{'AMDX6' }*$y*$y            +
          $header->{'AMDX7' }*($x*$x+$y*$y)    +
          $header->{'AMDX8' }*$x*$x*$x         +
          $header->{'AMDX9' }*$x*$x*$y         +
          $header->{'AMDX10'}*$x*$y*$y         +
          $header->{'AMDX11'}*$y*$y*$y         +
          $header->{'AMDX12'}*$x*($x*$x+$y*$y) +
          $header->{'AMDX13'}*$x*$cjunk;
    # Derivative of X model with respect to X.
    $fx = $header->{'AMDX1' }                  +
          $header->{'AMDX4' }*2*$x             +
          $header->{'AMDX5' }*$y               +
          $header->{'AMDX7' }*2*$x             +
          $header->{'AMDX8' }*3*$x*$x          +
          $header->{'AMDX9' }*2*$x*$y          +
          $header->{'AMDX10'}*$y*$y            +
          $header->{'AMDX12'}*(3*$x*$x+$y*$y)  +
          $header->{'AMDX13'}*(5*$x4+6*$x*$x*$y*$y+$y4);
    # Derivative of X model with respect to Y.
    $fy = $header->{'AMDX2' }                  +
          $header->{'AMDX5' }*$x               +
          $header->{'AMDX6' }*2*$y             +
          $header->{'AMDX7' }*2*$y             +
          $header->{'AMDX9' }*$x*$x            +
          $header->{'AMDX10'}*$x*2*$y          +
          $header->{'AMDX11'}*3*$y*$y          +
          $header->{'AMDX12'}*2*$x*$y          +
          $header->{'AMDX13'}*4*$x*$y*($x*$x+$y*$y);
    # Y plate model.
    $g =  $header->{'AMDY1' }*$y               +
          $header->{'AMDY2' }*$x               +
	  $header->{'AMDY3' }                  +
          $header->{'AMDY4' }*$y*$y            +
          $header->{'AMDY5' }*$y*$x            +
          $header->{'AMDY6' }*$x*$x            +
          $header->{'AMDY7' }*($x*$x+$y*$y)    +
          $header->{'AMDY8' }*$y*$y*$y         +
          $header->{'AMDY9' }*$y*$y*$x         +
          $header->{'AMDY10'}*$y*$x*$x         +
          $header->{'AMDY11'}*$x*$x*$x         +
          $header->{'AMDY12'}*$y*($x*$x+$y*$y) +
          $header->{'AMDY13'}*$y*$cjunk;
    # Derivative of Y model with respect to X.
    $gx = $header->{'AMDY2' }                  +
          $header->{'AMDY5' }*$y               +
          $header->{'AMDY6' }*2*$x             +
          $header->{'AMDY7' }*2*$x             +
          $header->{'AMDY9' }*$y*$y            +
          $header->{'AMDY10'}*$y*2*$x          +
          $header->{'AMDY11'}*3*$x*$x          +
          $header->{'AMDY12'}*2*$x*$y          +
          $header->{'AMDY13'}*4*$x*$y*($x*$x+$y*$y);
    # Derivative of Y model with respect to Y.
    $gy = $header->{'AMDY1' }                  +
          $header->{'AMDY4' }*2*$y             +
          $header->{'AMDY5' }*$x               +
          $header->{'AMDY7' }*2*$y             +
          $header->{'AMDY8' }*3*$y*$y          +
          $header->{'AMDY9' }*2*$y*$x          +
          $header->{'AMDY10'}*$x*$x            +
          $header->{'AMDY12'}*($x*$x+3*$y*$y)  +
          $header->{'AMDY13'}*(5*$y4+6*$x*$x*$y*$y+$x4);
    return ($f,$fx,$fy,$g,$gx,$gy);
}

# Routine to convert RA and Dec in radians to HMS.

sub Rad2HMS {
    my ($ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
    my ($pi) = 3.14159265359;
    # Convert RA to hours and Dec to degrees.
    $ra  *= 12/$pi;
    $dec *= 180/$pi;
    if ($dec >= 0) {
	$dc = "+";
    } else {
	$dc = "-";
    }
    $dec = abs($dec);
    # Convert to HMS format.
    $rh = int($ra);
    $rm = int(($ra-$rh)*60);
    $rs = ($ra-$rh-$rm/60)*3600;
    $dd = int($dec);
    $dm = int(($dec-$dd)*60);
    $ds = ($dec-$dd-$dm/60)*3600;
    return ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
}

# Routine to convert RA and Dec in degrees to HMS.

sub Deg2HMS {
    my ($ra,$dec) = @_;
    my ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
    # Convert RA to hours.
    $ra  /= 15;
    if ($dec >= 0) {
	$dc = "+";
    } else {
	$dc = "-";
    }
    $dec = abs($dec);
    # Convert to HMS format.
    $rh = int($ra);
    $rm = int(($ra-$rh)*60);
    $rs = ($ra-$rh-$rm/60)*3600;
    $dd = int($dec);
    $dm = int(($dec-$dd)*60);
    $ds = ($dec-$dd-$dm/60)*3600;
    return ($rh,$rm,$rs,$dc,$dd,$dm,$ds);
}

# Routine to generate color table.

sub Color_Table {
    my ($tab,$con,$bri) = @_;
    my ($gl) = [0,1];
    my ($gr) = [0,1];
    my ($gg) = [0,1];
    my ($gb) = [0,1];
    my ($rl) = [-0.50,0.00,0.17,0.33,0.50,0.67,0.83,1.00,1.70];
    my ($rr) = [ 0.00,0.00,0.00,0.00,0.60,1.00,1.00,1.00,1.00];
    my ($rg) = [ 0.00,0.00,0.00,1.00,1.00,1.00,0.60,0.00,1.00];
    my ($rb) = [ 0.00,0.30,0.80,1.00,0.30,0.00,0.00,0.00,1.00];
    my ($hl) = [ 0.00,0.20,0.40,0.60,1.00];
    my ($hr) = [ 0.00,0.50,1.00,1.00,1.00];
    my ($hg) = [ 0.00,0.00,0.50,1.00,1.00];
    my ($hb) = [ 0.00,0.00,0.00,0.30,1.00];
    my ($wl) = [ 0.00,0.50,0.50,0.70,0.70,0.85,0.85,0.95,0.95,1.00];
    my ($wr) = [ 0.00,1.00,0.00,0.00,0.30,0.80,0.30,1.00,1.00,1.00];
    my ($wg) = [ 0.00,0.50,0.40,1.00,0.00,0.00,0.20,0.70,1.00,1.00];
    my ($wb) = [ 0.00,0.00,0.00,0.00,0.40,1.00,0.00,0.00,0.95,1.00];
    my ($al) = [ 0.00,0.10,0.10,0.20,0.20,0.30,0.30,0.40,0.40,0.50,
		 0.50,0.60,0.60,0.70,0.70,0.80,0.80,0.90,0.90,1.00];
    my ($ar) = [ 0.00,0.00,0.30,0.30,0.50,0.50,0.00,0.00,0.00,0.00,
		 0.00,0.00,0.00,0.00,1.00,1.00,1.00,1.00,1.00,1.00];
    my ($ag) = [ 0.00,0.00,0.30,0.30,0.00,0.00,0.00,0.00,0.80,0.80,
		 0.60,0.60,1.00,1.00,1.00,1.00,0.80,0.80,0.00,0.00];
    my ($ab) = [ 0.00,0.00,0.30,0.30,0.70,0.70,0.70,0.70,0.90,0.90,
		 0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00];
    $con *= 10;
    if ($tab == 1) {
	# Grayscale.
	pgctab($gl,$gr,$gg,$gb,2,$con,$bri);
    } elsif ($tab == 2) {
	# Rainbow.
	pgctab($rl,$rr,$rg,$rb,9,$con,$bri);
    } elsif ($tab == 3) {
	# Heat.
	pgctab($hl,$hr,$hg,$hb,5,$con,$bri);
    } elsif ($tab == 4) {
	# Weird IRAF.
	pgctab($wl,$wr,$wg,$wb,10,$con,$bri);
    } elsif ($tab == 5) {
        # AIPS.
	pgctab($al,$ar,$ag,$ab,20,$con,$bri);
    }
    return;
}

# Routine to draw the NIFS slitlet grid.

sub NIFS_Grid {
    my ($x0,$y0,$xscale,$yscale) = @_;
    my ($i,$x);
    my ($ns) = 29;
    my ($y1) = $y0-1.5/$yscale;
    my ($y2) = $y0+1.5/$yscale;
    foreach $i (1..$ns-1) {
	$x = $x0+0.103*($i-$ns/2)/$xscale;
	pgmove($x,$y1);
	pgdraw($x,$y2);
    }
    return;
}

# Base 10 logarithmn.

sub log10 {
    my $n = shift;
	return log($n)/log(10);
}