I think Javascript is becoming less and less useful.
PHP can do a lot that Javascript does without the problem of having javascript disabled (perhaps by your IT department so you can't enable it).
CSS can do drop down menus and hover popups quite well enough.
However, JQuery and Ajax seems to be the latest whizz languages and they have taken Javascript to a new level.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.