Unfortunately your question seems a little vague. Are you using the CGI perl module? If you're not, you probably should be. The documentation for the CGI module goes into great detail about exactly what you are trying to accomplish. I'd start there.

On UNIX-ish systems (including Linux) you can usually just type "perldoc CGI" at the command line and if your perl installation is complete and set up correctly you'll get the documentation your looking for.

Good luck!