codice:
public class Home extends JFrame  {
	
	


	private JPanel contentPane;


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


	/**
	 * Create the frame.
	 */
	boolean chiave=false;
	public Home(){
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 663, 361);
		
		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
		
		JMenu mnNewMenu = new JMenu("File");
		
		
		
		menuBar.add(mnNewMenu);
		
		JMenuItem mntmRegistrati = new JMenuItem("Registrati");
		mntmRegistrati.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				Registrati registrati=new Registrati();
				registrati.setVisible(true);
			}
		});
		mnNewMenu.add(mntmRegistrati);
	
		JMenuItem mntmAccedi = new JMenuItem("Accedi");
		mntmAccedi.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				Accedi accedi=new Accedi();
				accedi.setVisible(true);
				chiave=accedi.isChiave();
			}
		});
		mnNewMenu.add(mntmAccedi);
		
		JMenuItem mntmEsci = new JMenuItem("Esci");
		mntmEsci.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				Accedi accedi=new Accedi();
				boolean chiave=accedi.isChiave();
				if(chiave==true){
					mntmEsci.setEnabled(true);
				}
			}
		});
		mntmEsci.setEnabled(false);
		
			
		mnNewMenu.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseClicked(MouseEvent e) {
				Accedi accedi=new Accedi();
				if(accedi.isChiave()==true){
					mntmEsci.setEnabled(true);
				}
			}
		});
		
		mnNewMenu.add(mntmEsci);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
	}
	
}