Hi mryang
I would definitely say convert to CSS.
If you have external stylesheet(s) then you haven't got to keep adding the same old thing to your pages, reducing the risk of errors and in turn reducing filesize significantally (not a fraction but reduced nevertheless).
As for the JavaScript, there are some good CSS rollover menus thus eliminating the need for the <script> and <noscript> tags reducing the filesize further.
Stu Nicholls | CSSplay | A CSS flyout menu that works in IE is similar to your side menu and
Stu Nicholls | CSSplay | Validating drop down cross-browser menu for the top. However check the copyright notice as permission must be granted to use the menus for commercial sites.
Hope this helps and rest assured that there are plenty of bods on here that are only too willing to help you if you get stuck or need that basic template.
