找不到 windowClosed

错误如下 :
D:\Program Files\JCreatorV4\MyProjects\ActionEvent1\WindowEvent2.java:20: 找不到符号
符号： 类 CloseFrameDialog
位置： 类 WindowEvent2
            CloseFrameDialog d = new CloseFrameDialog (this,"关闭","确实要关闭吗?");
            ^请问这是怎么回事?是JDK的版本不对吗?代码如下:import java.awt.*;
import java.awt.event.*;
public class WindowEvent2 extends Frame implements WindowListener{    public WindowEvent2() {
     setTitle("窗口关闭事件的处理");
     addWindowListener(this);
    }
    
      public void windowClosing(WindowEvent e){
        CloseFrameDialog d = new CloseFrameDialog (this,"关闭","确实要关闭吗?");
        d.setSize(200,100);
        d.setVisible(true);
       }
        
       public void windowClosed(WindowEvent e){}
   public void windowDeactivated(WindowEvent e){}
   public void windowActivated(WindowEvent e){}
   public void windowIconified(WindowEvent e){}
   public void windowDeiconified(WindowEvent e){}
   public void windowOpened(WindowEvent e){}public static void main (String[] args) {
   WindowEvent2 me = new WindowEvent2();
   me.setSize(200,100);
   me.setVisible(true);
}
    
    
}