点关闭按钮让面板关闭!

怎么修改?
import java.awt.event.*;
import java.awt.*;class TestStopWatch extends Frame
{
    public TestStopWatch()
    {
        addWindowListener(new WindowAdapter()
        {
            public void WindowClosing(WindowEvent e)
            {
                dispose();
                System.exit(0);
            }
        });
    }
    public static void main(String []args)
    {
        TestStopWatch sw=new TestStopWatch();
        sw.setSize(400,400);
        sw.setVisible(true);
    }
}