How to create a small box above selected text ( double click to select it )

I try to write a dictionary extension for Google Chrome. Now, I want to pop out a small box when I double click to select text . How can I implement it :) Or like this one ( Fastest Chrome ). They're written in javascript.

alt text http://img130.imageshack.us/img130/9721/abcjq.jpg Thanks so much !

Two links that may solve your question:

• Detecting a double-click on a Youtube URL with Javascript (uses JQuery)

• Detecting a double-click on a Youtube URL with Javascript (uses pure JS)

And since no one previously wanted to reply as answers, try the links mentioned above:

• http://www.codetoad.com/javascript_get_selected_text.asp

• http://www.sixrevisions.com/tutorials/javascript_tutorial/