Can Event Handlers Trigger PHP Code?

My question is can event handlers on form objects trigger PHP code? <input type="submit" name="submit" value="Submit Form" onclick='PHP CODE HERE'> Or even an "onsubmit" event handler on forms? If something like this is possible, could any of you tell me how? I've tried, and tried. I've used PHP tags inside the event handler <input type="submit" name="submit" value="Submit Form" onclick='<? PHP CODE HERE ?>'> But the result is that the event handler is blank <input type="submit" name="submit" value="Submit Form" onclick=''> since the interpreter hides any PHP code. Thus nothing happens on the event. Any help is appreciated.