public void addUser(String Nick,String Nombre, String Apellidos, String pass) { //ok
        try {
            String queryString = "INSERT INTO Usuarios( nick, nombre, apellidos, password) VALUES(?,?,?,?)";
            connection = getConnection();
            ptmt = connection.prepareStatement(queryString);
            ptmt.setString(1, Nick);
            ptmt.setString(2, Nombre);
            ptmt.setString(3, Apellidos);
            ptmt.setString(4, pass);
            ptmt.executeUpdate();
            System.out.println("Data Added Successfully");
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (ptmt != null) {
                    ptmt.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }