var DragBounds:Rectangle = new Rectangle(myMovie.x, myMovie.y, myMovie.width-box.width,myMovie.height-box.height);
box.addEventListener(MouseEvent.MOUSE_DOWN, Drag);
function Drag(event:MouseEvent):void
{
box.startDrag( false,DragBounds);
}
stage.addEventListener(MouseEvent.MOUSE_UP, Drop);
function Drop(event:MouseEvent):void
{
box.stopDrag();
}