How to have a MOUSE_OVER event when dragging over?

Hello, I have a item1 that needs to have a MOUSE_OVER effect when item2 is dragged over it. How can I do that?

item1.addEventListener(MouseEvent.MOUSE_OVER, backover);

function backover (e:MouseEvent):void {
    this.item1 .gotoAndStop(2);

This works with a regular mouse over but not when dragging another object over it.