 		protected function handleMouseDown(event:MouseEvent):void
 		{			
 			updateMouseMode(InteractionController.DRAG); // modifier keys may have changed just prior to pressing mouse button, so update mode now
+			
+			//for detecting change between drag start and drag end
+			detectLinkableObjectChange( handleMouseDown, layers );
 			
 			mouseDragActive = true;
 			// clear probe when drag starts

		// this function can be defined with override by extending classes and call super.handleMouseClick(event);
		protected function handleMouseClick(event:MouseEvent):void
		{
			clearSelection();
			handleMouseEvent(event);
		}
		

				}
				case InteractionController.SELECT:
				{
					if ( dragReleased && !detectLinkableObjectChange( handleMouseDown, layers ))
						clearSelection();
				   	else if (mouseDragActive)
						handleSelection(event, _mouseMode);
					break;
				}
