New to Java

I'm fairly new to java but I don't understand why I'm getting this ActionListener Error:
Event4.java:7: Event4 is not abstract and does not override abstract method acti
onPerformed(java.awt.event.ActionEvent) in java.awt.event.ActionListener
public class Event4 extends JFrame implements ActionListener

I'm supposed to create an inner class object that will respond to events
Here is my code:

import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Color;

public class Event4 extends JFrame implements ActionListener
{
	private JButton myButton;

	public static void main (String[ ] args)
	{
		JFrame f = new Event4( );
		f.setDefaultCloseOperation(EXIT_ON_CLOSE);
		f.setSize(250,170);
		f.setVisible(true);
	}

	public Event4( )
	{
		super("Event Demo 4");
		getContentPane( ).setLayout(new FlowLayout( ));
		myButton = new JButton("Example");
		
		getContentPane( ).add(myButton);
		myButton.addActionListener(new
			ActionListener()
			{
				public void actionPerformed(ActionEvent event)
				{
					getContentPane().setBackground(Color.RED);
				}


			});
		
	}

	
}

Any help is greatly appreciated, thanks in advance.