[undefined]

import flash.display.*;
import flash.events.*;
import flash.net.*;
 
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
loader.load(new URLRequest("1.jpg"));
addChild(loader);
stage.addEventListener(Event.RESIZE, update);
function onComplete(e:Event):void 
{
	e.target.removeEventListener(Event.COMPLETE, onComplete);
	(e.target.content as Bitmap).smoothing = true;
	update();
}
function update(e:Event = null):void {
	loader.scaleX = loader.scaleY = 1;
	var scale:Number=Math.min(stage.stageWidth /loader.width,stage.stageHeight/loader.height);
	loader.scaleX = loader.scaleY = scale;
	loader.x = stage.stageWidth * 0.5 - loader.width * 0.5;
	loader.y = stage.stageHeight* 0.5 - loader.height * 0.5;
}

Писал не в flash ide,поэтому могут быть ошибки, но вроде все верно.