circle

I have been trying to write this circle method that should move the
circle two places of width to the right, the method I have written I get
errors from is below

 public void moveRight()
 
{
  moveHorizontal(60);
}

* The class Circle defines a shape with the characteristics of a circle.
 *
 * xxxxxxxxxxxx
 * xxxxxxxxxxxx
 */
 
public class Circle extends OUAnimatedObject
{
/* Instance variables */

   private int diameter;
   private CKColour colour;
   private int xPos;
   private int yPos;

   
   
   /**
    * Constructor for objects of class Circle with the default
characteristics.
    */
   public Circle()
   {
      this.diameter = 20;
      this.colour = CKColour.BLUE;
      this.xPos = 0;
      this.yPos = 0;
   }
   
   /* Instance methods */
   
   /**
    * Causes execution to pause for 500 milliseconds (half a second).
    */
   public void sleep()
   {
      try
      {
         Thread.sleep(500);
      }
      catch (Exception e)
      {
         System.out.println("Exception has occurred in the sleep()
method");
      }
   }
   
   
   /**
    * Sets the diameter of the receiver to the value of the argument
aDiameter
    */
   public void setDiameter(int aDiameter)
   {
      this.diameter = aDiameter;
      this.update();
   }
   
   /**
    * Returns the diameter of the receiver.
    */
   public int getDiameter()
   {
      return this.diameter;
   }
   
   /**
    * Sets the colour of the receiver to the value of the argument
aColour.
    */
   public void setColour (CKColour aColour)
   {
      this.colour = aColour;
      this.update();
   }
   
   /**
    * Returns the colour of the receiver.
    */
   public CKColour getColour ()
   {
      return this.colour;
   }
   
   /**
    * Sets the horizontal position of the receiver to the value of the
argument x.
    */
   public void setXPos(int x)
   {
      this.xPos = x;
      this.update();
   }
   
   /**
    * Returns the horizontal position of the receiver.
    */
   public int getXPos()
   {
      return this.xPos;
   }
   
   /**
    * Sets the vertical position of the receiver to the value of the
argument y.
    */
   public void setYPos(int y)
   {
      this.yPos = y;
      this.update();
   }
   
   /**
    * Returns the vertical position of the receiver.
    */
   public int getYPos()
   {
      return this.yPos;
   }
   
   /**
    * Returns a string representation of the receiver.
    */
   public String toString()
   {
      return "An instance of class "+ this.getClass().getName()
             + ": position (" + this.getXPos() + ", " + this.getYPos()
             + "), diameter " + this.getDiameter() + ", colour " +
this.getColour();
   }

   
   
  /**
   * Moves position of receiver two places to the right.
   */
  public void moveRight()
  
   {
    
      moveRight (20);

   }