Stop/Play movie/button

Right,
once again, I’ve got this idea for making a nice page hihi.

Allright, here goes;

-I record something from a game. Edit those movies. And save them as separate files.

-In flash, I load up the MAIN movie f.e., then I create an invisable button over some parts…when its clicked, it has to start playing movie2.mpg f.e.
And back, so when someone is done looking at page2(movie2.mpg) is has to go back to the main movie.

Now, What I need to know is;

The commands for loading a movie the correct way.
Import those movies
Preload? I don’t know how big the files are gonna be, so… I think something around 300-600kb.

Tia !