vider la scène

while (stage.numChildren > 0) stage.removeChildAt(0);
//ou
stage.removeChild(0);

var scene:Sprite = new Sprite();
var testSprite:Sprite = new Sprite();
		
var urlImage:URLRequest = new URLRequest("image.jpg");
var monLoader:Loader = new Loader();
[...]
public function Enigme1():void {
	addChild(scene);
	monLoader.load(urlImage);
	testSprite.addChild(monLoader);
	scene.addChild(testSprite);
	addListeners(testSprite);
}

private function addListeners(... objects):void {
	for (var i:int = 0; i < objects.length; i++) {
		objects[i].addEventListener(MouseEvent.MOUSE_DOWN, dragObject);
		objects[i].addEventListener(MouseEvent.MOUSE_UP, stopDragObject);
	}
}

private function dragObject(e:MouseEvent):void {
	e.currentTarget.startdrag();
}

private function dragObject(e:MouseEvent):void {
	getPosition(e.currentTarget);
	e.currentTarget.startDrag();
}

private function stopDragObject(e:MouseEvent):void {
	if (e.currentTarget.hitTestObject(getChildByName(e.currentTarget.name + "Target"))) {
		e.currentTarget.x = getChildByName(e.currentTarget.name + "Target").x + 25;
		e.currentTarget.y = getChildByName(e.currentTarget.name + "Target").y + 20;
		testFin();
	} else {
		e.currentTarget.x = xPos;
		e.currentTarget.y = yPos;
	}
	e.currentTarget.stopDrag();
}

private function addListeners(... objects):void {
	for (var i:int = 0; i < objects.length; i++) {
		objects[i].addEventListener(MouseEvent.MOUSE_DOWN, dragObject);
		objects[i].addEventListener(MouseEvent.MOUSE_UP, stopDragObject);
	}
}