This is a public domain script that simply shows you all the 
environmental information ($ENV{}) that is being passed from
the server.  Copy after the ---- line, chmod a+x and run.
---------------------
#!/usr/bin/perl 
   print "Content-type: text/html\n\n"; 
   print "<tt>\n"; 
   foreach $key (sort keys(%ENV)) { 
      print "$key = $ENV{$key}<p>"; 
   }