A tooltip widget/plugin in YUI3

I am writing an app and I want stack overflow like tool-tips updated with ajax. And I want it in AJAX too.

Please tell me if any such library already exists and otherwise will it be helpful to write a one 开发者_如何学运维from scratch.

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I found two solutions

1. The YUI3 Alloy Tooltip module. Which is poorly written and not suitable for my use.
2. The example provided by YUI3 http://developer.yahoo.com/yui/3/examples/widget/widget-tooltip.html

It is helpful and customizable.