ActionListener Error

Hi, every time I try to compile the code below I get the following error: "addActionListener(java.awt.event.ActionListen er) in javax.swing.AbstractBunnon cannot be applied to (Start)"

Can Anyone help me?
Thanks in advance.

Code:

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public class Start extends JFrame{

 
  public static void main(String[] args) {
    new Start();
  }

  public Start() {
   
    JFrame f = new JFrame("Menu");
    f.setSize(500, 500);
   
    Container content = f.getContentPane();
    content.setBackground(Color.blue);
    content.setLayout(new FlowLayout());
    JButton button1 = new JButton("Nieuw Spel"); //knop 1
    content.add(button1);
    f.setVisible(true);
   
    button1.setToolTipText("blablabla");
   
  }
  public void actionPerformed(ActionEvent event)
  {
      if(event.getSource() == button1){ //EVENT BUTTON 1 NOT NIET IN ORDE
        } 

}
}

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When you use addActionListener() you have to use an argument that is an instance of the the ActionListener interface. Your Start does not implement ActionListener unless you explicitly say so:

Code:

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public class Start extends JFrame implements ActionListener {

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