I just want to load a PNG or JPEG by pressing on a button...!

I have a bunch of buttons. On release, I want each button to load an image into a MC I have on the stage. So when each thumbnail is clicked, it just loads the next image. Very simple - thumbnails along the bottom, image loads above in a big space.

I’ve read everything, searched all over the net, but can’t seem to find the answer to my problem. What’s the deal? Isn’t there a simple behavior to attach to a button so that it loads an image into a movie clip on the stage?

Please help. I’ve been going in cirlces for 2 days now. I’m thinking this shouldn’t be so hard.

I’m working in Flash 8.