private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton3ActionPerformed
        if (t1.getText().isEmpty()) 
        {
            JOptionPane.showMessageDialog(this, "Please enter the server url");
        } 
        else if (t2.getText().isEmpty()) 
        {
            JOptionPane.showMessageDialog(this, "Please enter the port no");
        } 
        else if (t3.getText().isEmpty()) 
        {
            JOptionPane.showMessageDialog(this, "Please enter the username");
        } 
        else if (t4.getText().isEmpty()) 
        {
            JOptionPane.showMessageDialog(this, "Please enter the password");
        } 
        else if (t4.getText().isEmpty()) 
        {
            JOptionPane.showMessageDialog(this, "Please enter the database name");
        } 
        else 
        {
            String url = "jdbc:mysql://" + t1.getText() + ":" + t2.getText() +"/"+ t5.getText();
            String user = t3.getText();
            String password = t4.getText();
            prefs.put(SERVER_URL, url + "," + user + "," + password);
            jPanel2.setVisible(false);
            jPanel4.setVisible(true);
            jButton5.setVisible(true);
        }
    }//GEN-LAST:event_jButton3ActionPerformed