import java.awt.*; import java.awt.event.*; import javax.swing.*; public class CheckBoxFrame extends JFrame implements WindowListener{ private Container contentPane; public CheckBoxFrame(){ setTitle("BoxTest"); setSize(300, 200); addWindowListener(this); contentPane = this.getContentPane(); contentPane.add(new CheckBoxPanel()); } public void windowClosing(WindowEvent e){ System.exit(0); } public void windowActivated(WindowEvent e){} public void windowClosed(WindowEvent e){} public void windowDeactivated(WindowEvent e){} public void windowDeiconified(WindowEvent e){} public void windowIconified(WindowEvent e){} public void windowOpened(WindowEvent e){} }