内部类做监听器的问题<anonymous myframe$1> is not abstract and does not override abstract method actionPerformed

我用内部类做监听器,可是去报错<anonymous myframe$1> is not abstract and does not override abstract method actionPerformed(java.awt.event.ActionEvent),是怎么回事儿啊?请大家帮忙看看.先谢谢了.class myframe extends Frame{
    Button button1,button2;
    Clock clock;
    myframe(){
    button1=new Button("suspend");
        button2=new Button("resume");
        clock=new Clock();
        add(button1,BorderLayout.SOUTH);
        add(button2,BorderLayout.EAST);
        add(clock,BorderLayout.CENTER);
        button1.addActionListener(new ActionListener(){
         public void actionperformed(ActionEvent e){
         //if(e.getSource()==button1)
         clock.secondTime.stop();
         }
        });
        button2.addActionListener(new ActionListener(){
         public void actionperformed(ActionEvent e){
         //if(//e.getSource()==button1)
         clock.secondTime.start();
         }
        });
        setSize(400,400);
        addWindowListener(new WindowAdapter()
                            {
                             public void windowClosing(WindowEvent e)
                             {
                             System.exit(0);
                             }
        
                            });
        setVisible(true);
    }
}