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