private function init():void
    {
     sprite = new Sprite();
     addChild(sprite);
     sprite.graphics.beginFill(0xff0000);
     sprite.graphics.drawRect(0, 0, 100, 100);
     sprite.graphics.endFill();
     sprite.x = 100;
     sprite.y = 100;
     stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
    }