A standard rollover has an onMouseOver event and also an onMouseOut event. The first changes the image, the second changes it back. If you work out exactly what you want to happen when you roll over your various images, then you can write the code directly. You're doing a remote or disjoint rollover. You just don't want the onMouseOut event.
A couple of places to start...
But you're going to have to dig into the actual code.
Great--I discovered the onMouseEventbefore looking at this last night. Now I have a new question--I want to have a central part of the page that has overlapping web layers--different web layers for each state. So when I'm in the state that corresponds to 10x magnification for example, I can mouse over a part of the image and have it display text, while if Iwas in the state corresponding to 4x, I could mouse over the same spot(it would be a different picture) and have it display different text. Is that possible? All I've found so far is adobe help document that says web layers are shared between all states...which is a problem.
Thanks again so much!
For what you want to accomplish...you have to write the code. You don't do it in Fireworks. Fireworks is a graphics program. It isn't a code-assistance program. Fireworks can output some basic functionality for common effects, but even then, the code is fragile. It's only meant for prototypes, not for live sites. Anyway, you want to do something non-standard, therefore you need to write custom code. If you don't know how to code, then you'll need to learn.
SitePoint books are usually good:
You could also code this in Flash, Silverlight, or Java.