Full flash problem...again

Hi guys,
I am using this script:

Stage.scaleMode = "noScale";

Stage.align = "LT";

box2._x = Math.round((Stage.width/2)-(box2._width/2));
box2._y = Math.round((Stage.height/2)-(box2._height/2));

box2.onResize = function() {
	box2._x = Math.round((Stage.width/2)-(box2._width/2));
	box2._y = Math.round((Stage.height/2)-(box2._height/2));
};
Stage.addListener(box2);
box2.onResize();

When loading an external swf into box2, the code does not move the box to the middle when the browser is rescaled. What is the problem?