I have a little problem

I have a web page (principal.html) with two frames.
option.pl controls the left frame and main.pl controls the right frame.

Option.pl has almost all the code so when the page started, first i display default data, and redirect the left frame to the right one. So i take events on the left frame and change the right.

And now that i want to do is to catch an event from the right frame. How can i do that???