Rollover show image

We are developing a flash 8 swf that has 5 thumbnail buttons which when the mouse rolls over will display a larger image and when any of the individual buttons are clicked the viewer is taken to an external link. Just to make it a little more complicated five images are rotating in the background. This is probably not a complicated actionscript but as a first time flash user we could us a lot of help. See http://www.cyclingnews.com/ for a sample