I've been messing round with some php classes that allow me to use Ajax drop down menus and I've got far enough but I now need to know how to get the value of the select list.

What I want to do is when there is a change on the menu I want to pass its value off to a JavaScript function and pass it off into this PHP class.

I know its something like document.elementsomething.value but I am not a JavaScript person and I am not sure.

Thanks in advanced,
Mark