How to pass unknown number of variables to a function?

Hi everybody on this rainy morning! My problem: I give the user a form with a list of options with checkboxes. The list is long and not predictable - the values change always. I want to put the checked values (or all, that doesn't matter) in an array, to pass it to my function. How can I write those keys and values in an array? I suppose it will be best done with JS - but since I don't know JS ... Has anybody a ready solution? Thank's a lot! Uwe