How to recreate Stack Overflow's welcome bar

Stack Overflow has a horizontal welcome bar at the top. Can anyone suggest how can I implement a similar bar on my website? Is there JavaScript that defines this functio开发者_C百科n? I'm not technical but learning.

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use jquery. use jquery. use jquery.

for demo see

http://jsfiddle.net/uFhqt/4

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Dojo has an UpgradeBar that dopes this:

http://trac.dojotoolkit.org/browser/branches/1.6/dojox/widget/UpgradeBar.js

http://trac.dojotoolkit.org/browser/branches/1.6/dojox/widget/UpgradeBar