A Fixed Div With Javascript To Scroll When A Window Is Too Small. Doc Type Issue

I'm working on a site where I have to use a fixed DIV for the menu. www.atelier2architecten.nl/index2.php I'm trying to find a way to let the fixed div scroll horizontal. Because,

Solution 1:

Have you tried this:

$(window).scroll(function () {
   $('#menu').css('left', -($(window).scrollLeft()));
});

Tested in FF and Chrome.

P.S. Needs jQuery