Quote Originally Posted by Egg Bramhill View Post
If you're trying to do it with popup layers you can soon run into issues as it's not simple to close a popup layer on mouse-over.
It would be better having a base image on MouseOff and use JavaScript to change the base image as in the attached xar file. I'm sure Acorn could make it less abrupt on mouse over. I didn't use the MouseOut code.
Edit: Cleaned up the demo and xar file.

DEMO

JS Code Source
Egg, I tidied up your JavaScript to accommodate any number of images.
I couldn't really do much for the transition as it gets quite messy. I have a bodge in place.
I changed the masks to a local file so I could experiment with it. Massages shows you don't even need an image.

The use of onmouseover without onmouseout is very useful as a latch.
I might try for a CSS solution...

image-swap-js-2 - Acorn.xar

Acorn