if (dragNode == null) return;
            public void mouseReleased(MouseEvent e) {		// Send System Exclusive message		if (dragNode.ofsX != null)		    sendSysex(dragNode.senderX, dragNode.ofsX.get());		if (dragNode.ofsY != null)		    sendSysex(dragNode.senderY, dragNode.ofsY.get());	    }