[gb2world]

Just noticed that when Tal told you he does not see the <form> in firebug, you suggested that maybe it was firefox. Firebug often does not display incorrect code. You'll see it in the page source, but firebug does not know what to do with it since it is wrong.

Seems to me that this is even more evidence that your problem is that your age form is being incorrectly placed inside another form. If so - your solution is to move it to a valid location or revise the javascript you have copied to not use a form submission. You could verify that this is indeed the problem by trying to move that form to a valid location.