How to put title in JDesktopPane?

I'm developing software for an MVC (Model-view-controller) design video store with the Java Persistent Api Framework and the XML language. My question is: How do you place and edit title in JDesktopPane ?

Example:

Iwantedtochangethenamefrom"simple" to "video system". How do you do that?

Screen Source Code:

package formularios;
import classes_persistencia.AcessoDAO;
import classes_registros.Acesso;
import java.awt.BorderLayout;
import java.beans.PropertyVetoException;
import java.util.Calendar;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import classes_utilitarias.AlteraFundo;
import classes_utilitarias.GravaPosicao;
import java.awt.Color;
import java.awt.Component;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import javax.swing.JInternalFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;





public class FrmPrincipal extends javax.swing.JFrame {

    private AcessoDAO conexaoAcesso = new AcessoDAO();
    private Acesso registroAcesso = new Acesso();
    private ArrayList<Acesso> registrosAcesso = new ArrayList<>();

    public static int altera = 1;
    public static int elimina = 1;
    public static int insere = 1;
    public static int cadastroAtor = 1;
    public static int cadastroDiretor = 1;
    public static int cadastroGenero = 1;
    public static int cadastroFaixa = 1;

    private Date date = new Date();

    public static JInternalFrame enderecoJanelaAgenda = new JInternalFrame();
    public static JInternalFrame enderecoJanelaCliente = new JInternalFrame();
    public static JInternalFrame enderecoJanelaTitulo = new JInternalFrame();
    public static JInternalFrame enderecoJanelaUsuario = new JInternalFrame();
    public static JInternalFrame enderecoJanelaFornecedor = new JInternalFrame();
    public static JInternalFrame enderecoJanelaCalendario = new JInternalFrame();
    public static JInternalFrame enderecoJanelaAtores = new JInternalFrame();
    public static JInternalFrame enderecoJanelaGeneros = new JInternalFrame();
    public static JInternalFrame enderecoJanelaDiretores = new JInternalFrame();
    public static JInternalFrame enderecoJanelaPrecos = new JInternalFrame();
    public static JInternalFrame enderecoJanelaRelatorios = new JInternalFrame();
    public static JInternalFrame enderecoJanelaLocacoes = new JInternalFrame();
    public static JInternalFrame enderecoJanelaConfig = new JInternalFrame();
    public static JInternalFrame enderecoJanelaDevolucao = new JInternalFrame();
    private static String caminhoFundo = "";

    public FrmPrincipal(String usuarioLogado, int nivelAcesso) throws FileNotFoundException, IOException {

        initComponents();
        if(nivelAcesso == 4){

        }
        else{
            configuraAcessos(nivelAcesso);
        }

        File pasta= new File("c:/Singelo");
        File pasta1= new File("c:/Singelo/Imagens");
        pasta.mkdir();
        pasta1.mkdirs();


        add( mdi_principal, BorderLayout.CENTER );         
        FrmStatus status = new FrmStatus(usuarioLogado);
        mdi_principal.add(status);
        status.setVisible(true);

    }

Note: mdi_principal is JDesktopPane and Frm_principal is JFrame .