Getting users Screen Resolution

I’ve been looking for the past week for a way to find out when someone comes to my web page what their screen resolution is, etc. in CGI/Perl.
What I think is needed is to run a Java script, then pass that variable to CGI/Perl.
Can some please email me some simple code that will show me how to do this?
Here is my URL: http://linux-serv.mendocino.cc.ca.us/~thammack/ Click on “Final Project”