ActionScript 3.0 :: Repeat Pattern On ResizeStage?

I would like to create a repeating pattern using a bitmap from my library as a background. I would like the pattern to always fill the stage area when the brower window is scaled. The code below works, but I think it may not be the most efficient way to handle this. Seems to be a little slow. 
 
function onResizeStage(evt:Event):void{
backGroundSprite.graphics.beginBitmapFill(pattern(0, 0));
backGroundSprite.graphics.drawRect(0, 0, stage.stageWidth, stage.stageHeight);
backGroundSprite.graphics.endFill(); 
}