private boolean isVerticalWin(int player) throws Exception {
		boolean result = false;
		String playerSymbol;
		if ((player < 0) || (player > TicTacToeBoard.PLAYER_O)) {
			throw new Exception("Invalid player index -- must be 0 or 1");
		}
		if( player == PLAYER_X) {
			playerSymbol = X;
		} else {
			playerSymbol = O;
		}
		for (int col = 0; col < SIZE; col++) {
			if ((square[0][col] == square[1][col])
					&& (square[1][col] == square[2][col])
					&& (square[2][col] == playerSymbol)) {
				result = true;
				break;
			}
		}
		return result;
	}