[]问一下tween的一些参数怎么设置

package

{

	import laya.display.Sprite;

	import laya.utils.Ease;

	import laya.utils.Handler;

	import laya.utils.Tween;

	

	public class LayaAirDemo

	{

		private var sp:Sprite;

		private var num:int;

		public function LayaAirDemo()

		{

			Laya.init(550,400);

			sp=new Sprite();

			sp.graphics.drawCircle(0,0,50,"#00FFFF");

			Laya.stage.addChild(sp);

			sp.pos(100,100);

			Tween.to(sp,{x:500},1000,Ease.backIn,Handler.create(this,onTween1));

			

		}

		

		private function onTween1():void

		{

			// TODO Auto Generated method stub

			num  ;

			trace(num);

			Tween.clearTween(onTween1);

			Tween.to(sp,{x:100},1000,Ease.backIn,Handler.create(this,onTween2));

		}

		

		private function onTween2():void

		{

			// TODO Auto Generated method stub

			Tween.clearTween(onTween2);

			Tween.to(sp,{x:500},1000,Ease.backIn,Handler.create(this,onTween1));

		}

	}

}