ahah form values

Hi!

I try to use the ahah framework in a module.
I have a form with 3 selectboxes.
Every selectbox calls a function when it changes. THis function puts new content to a div-container.
This is already working.

But now i need to knwo the actual value of all three checkboxes in the callback function.
Can anyone tell me, how to get them?

Thanks in advance.

Nicolas