public void retryPortServer() {
        jButton.setEnabled(false);
        
        JLabel errorFields = new JLabel(
                "This combination of server and port number is not working.");
        JOptionPane.showMessageDialog(null, errorFields);
        
        // removing the old action listeners
        jTextField2.setText("4444");
        jTextField3.setText("localhost");
        jButton.setEnabled(true);
        this.setVisible(true);
    }