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

public class ApplicationFrame
    extends Frame {
  public ApplicationFrame() { this("ApplicationFrame v1.0"); }
  
  public ApplicationFrame(String title) {
    super(title);
    createUI();
  }
  
  protected void createUI() {
    setSize(500, 400);
    center();

    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        dispose();
        System.exit(0);
      }
    });
  }
  
  public void center() {
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension frameSize = getSize();
    int x = (screenSize.width - frameSize.width) / 2;
    int y = (screenSize.height - frameSize.height) / 2;
    setLocation(x, y);
  }
}