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

class JCheckBoxTest extends JFrame implements ChangeListener {
	JCheckBoxTest() {
		getContentPane().setLayout(new FlowLayout());

		JCheckBox cb = new JCheckBox("Off");
		cb.addChangeListener(this);
		getContentPane().add(cb);

		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setTitle("JCheckBoxTest");
		setSize(200, 100);
		setVisible(true);
	}
	public void stateChanged(ChangeEvent e) {
		JCheckBox cb = (JCheckBox)e.getSource();
		if (cb.isSelected()) {
			cb.setText("On");
		} else {
			cb.setText("Off");
		}
	}
	public static void main(String[] args) {
		new JCheckBoxTest();
	}
}