Change 2 frames in 1 url

I wanted to make a website for a friend of mine.
The website 's almost ready, only 1 thing.

I want 2 frames to be changed by clicking at a menu-item.
How can I make this happen?

Hope you know what I mean and you guys can help. :)

if you are using Dreamweaver you can use behaviors to do disjointed rollovers where if you mouseover one thing multiple things can change. You can change the "mouseover" event to "click" and that could work. I am not sure if that will work but it might.

-Ali