Background Scroll?

I dont know how easy it is, but I am looking for a side scroll!

I have been searching like crazy for a tutorial and still cant find one.

I want to learn how to do 2 layers, both moving in the same direction, right to left, and one layer is moving slower than the other one that is in front of it. So it looks like the camera is paning across the screen.

Does this make sense?

I have seen it done with action scripting, any help would be great. I did see the cloud background loop, but that is not what I have in mind. I think it is more like a loop then a scroll.

The example I am trying to copy just so that I know how to do the effect, is number 5 of the scrotum the puppy movies. If you do a search you can find it.