boolean checkHorizontal(char[][] board) {
		for (int i = 0; i < 9; i++) {
			int[] result = new int[9];
			for (int j = 0; j < 9; j++) {
				int temp = (int) board[i][j] - '0';
				if (temp == -2)
					continue; // for '.'
				else if (temp > 9 || temp < 1)
					return false;
				else {
					if (result[temp - 1] == 0)
						result[temp - 1] = 1;
					else
						return false;
				}
			}
		}
		return true;
	}