public void addPlayer(PlayerMP player)
  {
    try
    {
      Statement statement = conn.createStatement();
      String sql = "SELECT * FROM players WHERE username = '" + player.getUsername() + "'";
      //System.out.println(sql);
      ResultSet res = statement.executeQuery(sql);
      if (res.next())
      {
        System.out.println("Player " + player.getUsername() + "already exist");
        return;
      }
      sql = "INSERT INTO `players` "
            + "(`id`, `username`, `password`, `score`) "
            + "VALUES (NULL, "
            + "'" + player.getUsername() + "', "
            + "'" + player.getPassword() + "', "
            + "NULL);";
      statement.executeUpdate(sql);
      System.out.println("Succeed adding player" + player.getUsername());
    } catch (SQLException e) {
      e.printStackTrace();
    }
  }