Java SE (Java Platform, Standard Edition)

here is what i have:

class MyFrame extends JFrame{
MyFrame(){
MyPanel panel = new MyPanel();
getContentPane().add(panel);
setVisible(true);
etc...
}
}

class MyPanel extends JPanel implements ActionListener{
MyPanel(){
JButton quit = new JButton("quit");
add(quit);
etc...
}

public actionPerformed(ActionEvent e){
//I want to close JFrame is a click a button call exit here
//how do i close JFrame
}
}

please help. thanks