I have a little question about tiled backgrounds.

Say I have a 40x40px tileable background, that i want to tile all over the scene (note that it is a fullscreen flash-movie, in which the background is supposed to cover the entire window no matter how big it is).
I found a code-snippet which loops out the tiles in movieclips onto the _root.

My question is, is there any way to have the entire tile in a single movieclip so that i can control it?
What i'm going to do is have two separate background tiles, and when you switch between two different pages in the movie, the backgroundtile is supposed to fade into the other one.

http://www.strainworks.com/test/flash-stretch/test.html

There's a little demonstration of what i want to do, but with a 2 tiled images for background instead.