JDialog modal problem java gui

问题

I have this code which runs without any errors but it isn't running the way I planned. I'm trying to figure out why my "Continue" button is not being displayed when I click the button labeled "important!!".

The only thing which is being displayed is a blank pop up window which is part of the code JDialog and it set to modal and visible. I just can't figure it out. If anyone can help me I would appreciate it a lot.

JPanel hehePanel = new JPanel(new FlowLayout(FlowLayout.RIGHT,10,20));
JDialog dialog = new JDialog((JFrame)null);
dialog.getContentPane().add(hehePanel,BorderLayout.CENTER);
JButton hButton = new JButton("important!!");
JButton fButton = new JButton(" on construction !!");
JButton exitButton = new JButton("EXIT CAW ");
hehePanel.add(hButton);
hButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        final JPanel hehePanel = new JPanel();
        final JDialog dialog = new JDialog();
        dialog.getContentPane().add(hehePanel,BorderLayout.PAGE_END);
        dialog.toFront();
        dialog.setModal(true);
        dialog.pack();
        dialog.setLocationRelativeTo(null);
        dialog.setVisible(true);
        JButton closebutton = new JButton("Continue");
        closebutton.setActionCommand("continue");
        closebutton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                if (evt.getActionCommand().equals("continue")) {
                    dialog.dispose();
                }
            }
        });
        hehePanel.add(closebutton);
    }
});

hehePanel.add(fButton);
hehePanel.add(exitButton);