Replacing image with text on mouseover

Ok I’ve searched like crazy on this topic, but can’t seem to find any help. Here’s what I’d like to do:

I want to have an image displayed as a link, and on mouseover the image disappears and is replaced by text. But, obviously in the spirit of simplified CMS I don’t want to have to create an image to replace it. I just want to replace it with text via HTML/Javascript.

Is this possible?