Script to describe something - new lines below if mouseover

[Azam.net]

I've seen some sites where, if you move your mouse over a bit of text or click on the text, a few lines appear below it in which the webmaster can provide details about the text. I don't know what this functionality is called, so can't find it any of the script sites.

Alternative would be a script which described the text in a TITLE or ALT tag format, but with larger font and scope for longer text.

Thanks very much.

[_Aerospace_Eng_]

http://www.dynamicdrive.com/dynamicindex5/dhtmltooltip.htm