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: http://www.dhtmlx.com/docs/products/dhtmlxTree/index.shtml

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: http://docs.sencha.com/ext-js/4-1/#!/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:

http://mattberseth.com/blog/2007/12/creating_an_outlook_navigation.html

Do you know where I could get such a script? This script here: http://dev.sencha.com/deploy/ext-4.1.0-gpl/examples/layout/accordion.html 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.