import java.awt.*;
import java.awt.event.*;

public class MainFrame extends Frame
              implements WindowListener
{
  // 1. Working constructor --------------------
  public MainFrame(String title) 
  { 
    super(title);
    addWindowListener(this); // Window events
    setSize(300, 250);       // Default size
    setLayout(new FlowLayout(FlowLayout.CENTER));
  }

  // 2. Default constructor ---------------------
  public MainFrame()
  {
    this("Untitiled"); 
  }

  // 3. Quit the application
  public void quitApp()
  {
    dispose();
    System.exit(0);
  }

  // 4. WindowListener methods -------------------
  public void windowOpened(WindowEvent we) {}
  public void windowClosed(WindowEvent we) {}
  public void windowIconified(WindowEvent we) {}
  public void windowDeiconified(WindowEvent we) {}
  public void windowActivated(WindowEvent we) {}
  public void windowDeactivated(WindowEvent we) {}
  public void windowClosing(WindowEvent we)
  {
    quitApp();
  }
}