private void createMainMenu(JMenuBar menuBar) {
        JMenu mainMenu = new JMenu("Main");
        mainMenu.setMnemonic(KeyEvent.VK_M);

        menuBar.add(mainMenu);

        JMenuItem startSimulationButton = new JMenuItem("New simulation...",
                KeyEvent.VK_N);
        startSimulationButton.addActionListener(new StartNewSimulationDialog(this));
        mainMenu.add(startSimulationButton);
        mainMenu.addSeparator();

        JMenuItem modifySettingsButton = new JMenuItem("Settings...",
                KeyEvent.VK_S);
        modifySettingsButton.addActionListener(new ModifySettings(this));
        mainMenu.add(modifySettingsButton);
        mainMenu.addSeparator();

        JMenuItem exitProgramButton = new JMenuItem("Exit",
                KeyEvent.VK_E);
        exitProgramButton.addActionListener(new ProgramShutdown(this));
        mainMenu.add(exitProgramButton);
    }