public Enter(String title) {
        super(title);
        this.setLayout(new BorderLayout());
        buttonList = new ButtonList();
        tabs = new TabPane();
        Container contentPane = getContentPane();
        contentPane.add(buttonList,BorderLayout.NORTH);
        contentPane.add(tabs,BorderLayout.CENTER);
        setSize(700, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }