Zoom In and Zoom Out

I have searched the threads and found there is no simple explanation as to how to do this. What I have is a map of the U.S. I want people to click on a state and have the US zoom into that state. While zoomed in, they can click on a close state and have it zoom to that state. An example can be found here:

http://backspace.com/mapapp/ (Scroll Down to the US Map)

This is exactly the thing I want, but in flash. I think all I need is a simple script to zoom in on a point relative to the mouse. Please Help!

Thanx