#!C:/perl/bin/perl.exe
use CGI;
$query = new CGI;

$xcoord= $query->param('xcoord');
$ycoord= $query->param('ycoord');
$xmin= $query->param('xmin');
$xmax= $query->param('xmax');

#---------------------------

$b = (17/($xmax - $xmin));
$a = -1*($b*$xmin);

$xcoordnew= $a + $b*$xcoord;
$ycoordnew= $a + $b*$ycoord;

$xcoordnew = sprintf("%.0f", $xcoordnew);
$ycoordnew = sprintf("%.0f", $ycoordnew);

#---------------------------
 
print $query->header;
print $query->start_html(-title=>'2D Graph Demo');
print "<FONT FACE = 'arial' SIZE = '2'>";

print "<CENTER>";
print "<TABLE  background='/images/2dback360.jpg' border='0' cellspacing='0' cellpadding='0'>";

for($y = 0; $y <= 17; ++$y){
  print "<TR>";
  for($x = 0; $x <= 17; ++$x){
     print "<TD>";
     if($xcoordnew == $x && $ycoordnew ==$y){
	   print "<IMG SRC='/images/dot.gif' >";
     }
	 else{
	   print "<IMG SRC='/images/blank.gif' >";
	 }
     print "</TD>";

   }
print "</TR>";
}
print "</TABLE>";
print "</CENTER>";

print "Original (x, y) coordinates: ($xcoord, $ycoord)<BR>";
print "Transformed coordinates: ($xcoordnew, $ycoordnew)<BR>";
  
print $query->end_html;