public synchronized void mouseReleased(MouseEvent me) {
		xm = me.getX();
		ym = me.getY();
		onScreen = xm >= 0 && ym >= 0 && xm < canvas.getWidth() && ym < canvas.getHeight();
		if (me.getButton() == MouseEvent.BUTTON1) mb0 = false;
		if (me.getButton() == MouseEvent.BUTTON3) mb1 = false;
		if (me.getButton() == MouseEvent.BUTTON2) mb2 = false;

	}