import java.util.* ;
import java.io.* ;
import java.awt.* ;
import java.awt.event.* ;
import javax.swing.* ;
import javax.swing.event.* ;

class TerminationListener implements WindowListener {
    public void windowActivated(WindowEvent e) {}
    public void windowClosed(WindowEvent e) {}
    public void windowClosing(WindowEvent e) {
        System.exit(0) ;
    }
    public void windowDeactivated(WindowEvent e) {}
    public void windowDeiconified(WindowEvent e) {}
    public void windowIconified(WindowEvent e) {}
    public void windowOpened(WindowEvent e) {}
}

class DialoguePanel extends JPanel implements ActionListener {

    public DialoguePanel() {

        display = new JTextField(20) ;
        display.setEditable(false) ;
        add(display) ;

        JButton button = new JButton("change") ;
        button.addActionListener(this) ;
        add(button) ;
    }


    public void actionPerformed(ActionEvent evt) {
        String text = JOptionPane.showInputDialog(this,
                              "Input new text",
                              "Change Displayed Text", 
                              JOptionPane.QUESTION_MESSAGE) ;
       
        if(text != null) display.setText(text) ;
    }

    private JTextField display ;
}

public class DialogueTest {
    public static void main(String [] args) {

        JFrame frame = new JFrame() ;

        frame.setTitle("Dialogue") ;
        frame.setSize(450, 300) ;

        frame.addWindowListener(new TerminationListener()) ;

        frame.getContentPane().add(new DialoguePanel()) ;

        frame.setVisible(true) ;
    }
}