How Do I make a picture go back and forth flashing, 3 pictures?

Question

I think im supposed to use layers,
Im using Photoshop Elements 6.0
Can some one explain it please,
And how to time it.

Answer 1

Well, I would do it with animation and make an animated GIF, so does your software make those?

Answer 2

I have 3.0, so I'm not sure it's the same...
Put the three images on different layers, the order will be from top to bottom. When you save it, save for web and then save as a gif. Check animate, set it how you want it to be, and then hit save and save as normal.
There should be something that says frame delay, which is the time the frames will stay. And if you want it to keep going, then set it on loop.