public void removeRedBackground(int x, int y) {
		if (redPanel[x][y] != null) {
			redPanel[x][y].setVisible(false);
		}
		redPanel[x][y] = null;
		paintImmediately(CHECKERSIZE * y, CHECKERSIZE * x
				, CHECKERSIZE * (y + 1), CHECKERSIZE * (x + 1));
	}