[Sweet07]

Я разобрался:

function tweenin (e:MouseEvent):void{
	bar.addEventListener(Event.ENTER_FRAME, moveBox);
	var MousePos:Number = mouseY;
	var ms:Tween = new Tween(scrollHandle, "y", None.easeOut,scrollHandle.y, MousePos ,1,true);
	if (MousePos == scrollHandle.y) {
bar.removeEventListener(MouseEvent.CLICK, tweenin);
bar.removeEventListener(Event.ENTER_FRAME, moveBox);
}