Animating a box using actionscript

Hi,

i want to make a box appear from nowhere using actionscript,i have a small box 5 width by 5 height, and i want it to go to 300 width and then go to 300 height. I don’t want to tween it cos using actionscript is probably a more effective way of doing it.

I don’t know how this is done, does anyone have any ideas?

speed = 10;
box_mc.onEnterFrame = function() {
	if (this._width<300) {
		this._width += speed;
		this._height += speed;
	} else {
		delete this.onEnterFrame;
	}
};