JInternalFrame

package Sistema;

import java.awt.Cursor;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.swing.ImageIcon;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

import com.towel.swing.img.JImagePanel;

public class Menu extends JFrame {

	/**
	 * 
	 */
	private static final long serialVersionUID = 7639857177185904971L;
	private JPanel contentPane;
	/**
	 * Create the frame.
	 */
	public Menu() {
		setExtendedState(Frame.MAXIMIZED_BOTH);
		setName("fameMenu");
		setTitle("Menu Principal");
		setBounds(100, 100, 450, 300);

		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
		
		JMenu mnNewMenu = new JMenu("Clientes");
		mnNewMenu.setIcon(new ImageIcon(Menu.class.getResource("/Imagens/User-Clients-icon.png")));
		mnNewMenu.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
		menuBar.add(mnNewMenu);
		
		JMenuItem mntmNewMenuItem = new JMenuItem("Cadastrar");

		mntmNewMenuItem.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
		mntmNewMenuItem.setIcon(new ImageIcon(Menu.class.getResource("/Imagens/Office-Client-Male-Light-icon.png")));
		mnNewMenu.add(mntmNewMenuItem);
		
		JMenuItem mntmNewMenuItem_1 = new JMenuItem("Editar");
		mntmNewMenuItem_1.setIcon(new ImageIcon(Menu.class.getResource("/Imagens/Actions-edit-rename-icon.png")));
		mnNewMenu.add(mntmNewMenuItem_1);
		
		JMenu mnNewMenu_1 = new JMenu("Close");
		mnNewMenu_1.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
		mnNewMenu_1.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseClicked(MouseEvent arg0) {
				System.exit(0);
			}
		});
		
		JMenu mnNewMenu_2 = new JMenu("Or\u00E7amentos");
		mnNewMenu_2.setIcon(new ImageIcon(Menu.class.getResource("/Imagens/dollar-icon.png")));
		menuBar.add(mnNewMenu_2);
		mnNewMenu_1.setIcon(new ImageIcon(Menu.class.getResource("/Imagens/Actions-edit-delete-icon.png")));
		menuBar.add(mnNewMenu_1);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JImagePanel imagePanel = new JImagePanel((BufferedImage) null);
		try {
			imagePanel.setImage("D:\\Documents and Settings\\y7vc\\workspace\\Balanca\\src\\Imagens\\balancas_02_72.jpg");
		} catch (IOException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
		imagePanel.setBounds(-11, 0, 1294, 939);
		contentPane.add(imagePanel);		
		
		final JDesktopPane desktopPane = new JDesktopPane();
		desktopPane.setBounds(0, 0, 1, 1);
		contentPane.add(desktopPane);
		
		mntmNewMenuItem.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseClicked(MouseEvent arg0) {
				
                          //Meu problema está nesta etapa
          final CadastroClientes t = new CadastroClientes();
				t.setTitle("teste");
				t.setMaximizable(true);
				t.setBounds(28, 11, 596, 477);
				
				desktopPane.add(t);
				desktopPane.moveToFront(t);
				
			}
		});
		
	}

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					Menu frame = new Menu();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
}