Help loading a random background full screen

programming flash
1

In the bottom layer of my main movie, Id like to put a random background image which loads on entering the frame and stretches to full screen. I would like to use a preloader for the image so Im trying to load a swf using this which I found here:

http://www.kirupa.com/developer/mx/loadingrandombackground2.htm

choice = Math.round(Math.random()*5);
switch (choice) {
case 0 :
    location.loadMovie("image0.swf");
    break;
case 1 :
    location.loadMovie("image0.swf");
    break;
case 2 :
    location.loadMovie("image0.swf");
    break;
case 3 :
    location.loadMovie("image0.swf");
    break;
case 4 :
    location.loadMovie("image0.swf");
    break;
case 5 :
    location.loadMovie("image0.swf");
    break;
}

but I could not get it to stretch full screen. How do I get the externally loaded swf to stretch full screen and be able to resize via a listener from within my main movie?

Thanks!
Rich