Multiline tooltip if Firefox

Firefox - only browser, that doesn't support symbol of lines break ("\n") in tooltips (attribute "title" of html elements). This problem you can solve if install browser extension Handy Xtra Stuff and choose in its settings:
Popup ALT text, unless TITLE text exists

Tested with Firefox 3.5.2 and Handy Xtra Stuff 3.1.0.
This post in Russian.