@Override
    public void actionPerformed(ActionEvent event) {
        Object source = event.getSource();

        if (source.equals(itemNewGame)) {
            // start a new Game
            new GraphicalUIMenuNewGame(controller);

        } else if (source.equals(itemExitGame)) {
            // exit the Game
            int confirm = JOptionPane.showConfirmDialog(this,
                    "Wollen Sie diese Anwendung wirklich beenden?",
                    "Programm beenden", JOptionPane.YES_NO_OPTION);
            if (confirm == JOptionPane.YES_OPTION) {
                System.exit(0);
            }

        } else if (source.equals(itemShowStats)) {
            // show Statistics
            JOptionPane.showMessageDialog(null, controller.getStatistic());
        }
    }