Code for hiding a div on mouseover:
<div style="display: block;" onmouseover="this.style.display=none;" onmouseout="this.style.display=block;"></div>
Code for changing an image on mouseover
<img src="images/myimage.gif" onmouseover="this.src='images/myimageoff.gif';" onmouseout="this.src='images/myimage.gif';">
Does that help?
ZipperJJ: The former returns an error on mouseover telling me that “none” is undefined, and on mouseout saying the same thing for “block”.
The latter works fine, I just need to cut out a segment of my background image that’s the same size as the image in the div, so that I can set that as the src for the mouseover. Still, that’s simpler than trying to teach myself how to use a CSS in a day.
Thanks! 
sorry, missing some quotes in the div code.
<div style="display: block;" onmouseover="this.style.display='none';" onmouseout="this.style.display='block';"></div>
Brilliant!
I’m sure that tomorrow, when I’ve had some rest and am able to understand things again, I’ll look over this thread, realize that the solution was obvious, and smack myself upside the head. In the meantime, another thanks to everyone for the assistance.