Hover over with images

Hi,

I have a small flash piece to work on. It can be seen here:
http://mgdesign.hostultra.com/worldmap

I need to make an image display when the user hovers over the location spots.

I.e. if the user hovers over Chicago it will show a picture of someone who works there.

What would be the best way to get his to work?

anyone? :shifty: