Menu-Bar For Web-Application

Does anyone of you know a good menu-bar for a big web-application, made in javascript?

I need a menu-bar for the left side of my Yii powered web application…

I found scripts like this:

Do you think it would be a good solution to use such a menu bar or do you have other/better suggestions?

I would like a menu-bat that’s resizable like this one:!/example/portal/portal.html, but this script is LARGE and HEAVY!

EDIT: I would like to have a menu like this Outlook-menu-bar because it’s very user-friendly:

Do you know where I could get such a script? This script here: is really heavy…

I would suggest to use some kind of a framework for this. So yeah, DHTMLX is a good candidate.

I am studing The Dojo Toolkit at the moment, the latest 1.8 version seems promising.