lucy24 - 12:21 am on Nov 23, 2012 (gmt 0)

In javascript you start with "onhover" to call a function. (There are other ways but that's the most straightforward.)

In raw html you can do it with image maps combined with a title attribute. Or did you mean "title" when you said "alt"? You'd almost have to, since alts don't simply appear.

It might be easier if you explained what you're really after. MMN without the M? "Click here" in case the user doesn't know how to operate a link?

If you're looking for exact cut-and-paste code you have come to the wrong forum :(