New to Java

import java.awt.*;
import java.awt.event.*;
import java.awt.ActiveEvent;
import java.applet.*;
public class MoveIt extends Applet implements ActionListener
{
	private Image cup;
	private Panel keyPad;
	public int yaxis = 15;
	public int xaxis = 15;
	private Button keysArray[];
	
	public void init()
	{
		cup = getImage(getDocumentBase(), "cup.gif");
		Canvas myCanvas = new Canvas();
		setBackground(Color.blue);
		setLayout(new BorderLayout());
		
		Button up = new Button("Up");
		Button down = new Button("Down");
		Button right = new Button("Right");
		Button left = new Button("Left");
		Button center = new Button("Center");
		
		add(myCanvas, BorderLayout.NORTH);
		add(keyPad, BorderLayout.SOUTH);
		
		keyPad.add(up, BorderLayout.NORTH);
		up.addActionListener(this);
		keyPad.add(down, BorderLayout.SOUTH);
		down.addActionListener(this);
		keyPad.add(right, BorderLayout.EAST);
		right.addActionListener(this);
		keyPad.add(left, BorderLayout.WEST);
		left.addActionListener(this);
		keyPad.add(center, BorderLayout.CENTER);
		center.addActionListener(this);
	}
	public void paint( Graphics g )
	{
		g.drawImage( cup, xaxis, yaxis, this );
	}
	public void ActionPerformed(ActionEvent e)
	{
		String action = e.getActionCommand();
		if(action.equals("Up"))
		{
			yaxis = yaxis - 15;
		}
		if(action.equals("Down"))
		{
			yaxis = yaxis + 15;
		}
		if(action.equals("Left"))
		{
			xaxis = xaxis - 15;
		}
		if(action.equals("Right"))
		{
			xaxis = xaxis + 15;
		}
		if(action.equals("Center"))
		{
			xaxis = 125;
			yaxis = 60;
		}
	}
}

How come there is an error:
The type MoveIt must implement the inherited abstract method
ActionListener.actionPerformed(ActionEvent)

What the hell does that mean?