static void connect () {
      try {
          Class.forName ("org.gjt.mm.mysql.Driver");
          conn = DriverManager.getConnection (
                 "jdbc:mysql://localhost:3306/mysql");
      }
      catch (SQLException sqle) {
          System.out.println ("SQL exception:" + sqle.getMessage ());
          System.out.println ("SQLState:"      + sqle.getSQLState ());
          System.out.println ("VendorError:"   + sqle.getErrorCode ());
          System.exit (-1);
      }
      catch (Exception sqle) {sqle.printStackTrace ();}
  }