Menu Flyout using YUI or Jquery

I would like to create a flyout menu exactly like ho开发者_如何转开发w it is on Walmart.com. Could somebody help me with this.

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Well here is something to start you off, you could modify this to be vertical, it makes use of jQuery.

http://www.sohtanaka.com/web-design/mega-drop-downs-w-css-jquery/