package {
	import flash.display.Stage;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;
	import flash.events.Event;
	import flash.display.Sprite;
	import flash.display.MovieClip;
	
	public class StageResize extends MovieClip
	{
		private var target_mc:MovieClip;
		private var stageW:Number = stage.stageWidth;
		private var stageH:Number = stage.stageHeight;
		private var stageR:Number = target_mc.width / target_mc.height;
		
		public function StageResize()
		{
			this.stage.scaleMode = StageScaleMode.NO_SCALE;
			stage.align = StageAlign.TOP_LEFT;
			this.stage.addEventListener(Event.RESIZE, this.BgResize);
			this.BgResize(null);
		}
		
		public function BgResize()
		{
			target_mc = bg;
			bg.x = stageW / 2;
			bg.y = stageH / 2;
			
			if (stageW / stageH >= stageR) {
				bg.width = stageW;
				bg.scaleY = bg.scaleX;
			} else {
				bg.height = stageH;
				bg.scaleX = bg.scaleY;
			}
		}
	}
}

var BG:StageResize = new StageResize();
addChild(BG);