Preventing Overlap on Hit Test

programming flash
1

I have searched the web for a solution and found none.;(

I have two rectangles, one of which is draggable, and when hitTestObject occurs I want to prevent the overlap.

here is the code:

[FONT=Courier New]addEventListener(Event.ENTER_FRAME, detectColl);

redSquare.addEventListener(MouseEvent.MOUSE_DOWN, grabIt);
redSquare.addEventListener(MouseEvent.MOUSE_UP, dropIt);

function grabIt(event:MouseEvent):void {
event.target.startDrag(false);
}

function dropIt(event:MouseEvent):void {
event.target.stopDrag();
}

function detectColl(event:Event):void{

if (redSquare.hitTestObject(greenSquare)){
    [COLOR=Red]????[/COLOR]
    
}

}

[/FONT]