Running slow

1

I use full browser flash using code from below. After resizing internet browser(IE) few times, my flash is begining to run slowly. Anyone help me to understand why? Thanks…


stop();
Stage.scaleMode = "noScale";
Stage.showMenu = false;
MC._x=Math.ceil(Stage.width/2);
MC._y=Math.ceil(Stage.height/2);
import flash.display.BitmapData;
var pattern:BitmapData = BitmapData.loadBitmap("patern");
function createTiles():Void {
 
        with (_level0) {
                beginBitmapFill(pattern);
                moveTo(0, 0);
                lineTo(Stage.width, 0);
                lineTo(Stage.width, Stage.height);
                lineTo(0, Stage.height);
                lineTo(0, 0);
                endFill();
        }
 
}
createTiles();
 
var stageL:Object = new Object();
addListener
stageL.onResize = function(){
createTiles();
MC._x=Math.ceil(Stage.width/2);
MC._y=Math.ceil(Stage.height/2);
}
Stage.addListener(stageL);