Several things could be wrong. You can go through the "Troubleshooting Perl CGI scripts" guide at
http://www.perl.org/troubleshooting_CGI.htmlIf, after that, you can demonstrate that you've read the FAQs and that your problem isn't something simple that can be easily answered, you'll probably receive a courteous and useful reply to your question if you post it on comp.infosystems.www.authoring.cgi (if it's something to do with HTTP or the CGI protocols). Questions that appear to be Perl questions but are really CGI ones that are posted to comp.lang.perl.misc are not so well received.
The useful FAQs, related documents, and troubleshooting guides are listed in the CGI Meta FAQ:
http://www.perl.org/CGI_MetaFAQ.html