Full Browser Flash - Animated Background instead of Bitmap

Hi

I have managed to make a full browser flash website where the background is a basic bitmap image which redraws itself in the background. I used the BitmapData class for this purpose and the actionscript for that is as follows.

import flash.display.BitmapData;

main._x = Stage.width / 2;
main._y = Stage.height / 2;

var rotate:BitmapData = BitmapData.loadBitmap ("rotate");

function fillBG() {
    this.beginBitmapFill(rotate);
    this.moveTo (0,0);
    this.lineTo (Stage.width, 0);
    this.lineTo (Stage.width, Stage.height);
    this.lineTo (0, Stage.height);
    this.lineTo (0,0);
    this.endFill();
}

fillBG();

var.stageL: Object = new Object ();
stageL.onResize =  function ();
    fillBG();
    main._x = Stage.width / 2;
    main._y = Stage.height / 2;

}
    
Stage.addListener(stageL);

However what i am trrying to achieve is something to this effect (see website below)

http://www.animallogic.com/

You see the background is not a bitmap it is a rotating movie of numerous bitmaps (hence a movie clip). To achieve this what changes need to be made to the actionscript Do you still call the BitmapData class to load a bitmap? How do you adjust that to load a flash movie instead of a single bitmap? quite confused.

If someone can spell this out for me i would be greatly appreciated

Thanks