flash as2 鼠标滚轮事件

var mouseListener:Object = new Object();
            mouseListener.onMouseWheel = function(delta,image) {
                  if (delta>0) {
                     image._xscale *= 1.1;
                     image._yscale *= 1.1;
                     //image.container._rotation += delta;
                  }
                  if (delta<0) {
                     image._xscale *= 0.9;
                     image._yscale *= 0.9;
                     //image.container._rotation += delta;
                  }
            };   
            Mouse.addListener(mouseListener);