     private var _clickOffset:Point;
     
     /**
-     *  The clickOffset is the point in the local coordinates of 
-     *  the thumb where the last mouse down event occurred. This
-     *  is used by calculateNewValue() to determine what value
-     *  the thumb has been dragged to.
+     *  The point in the local coordinates of 
+     *  the thumb button where the last mouse down event occurred. 
+     *  This property is used by the <code>calculateNewValue()</code> method 
+     *  to determine the value that the thumb button has been dragged to.
+     *
+     *  @return Point object rerpresenting, in the local coordinates of 
+     *  the thumb button, where the last mouse down event occurred. 
      */
     protected function get clickOffset():Point
     {

    }

    /**
     *  Capture mouse-move events anywhere on or off the stage.
     *  First, we calculate the new value based on the new position
     *  using calculateNewValue(). Then, we move the thumb to 

    }

    /**
     *  Set the position of the thumb button. 
     *
     *  <p>Subclasses should override this method to position 
     *  the thumb button.</p>
     *
     *  @param thumbPos The new position of the thumb button.
     */
    protected function positionThumb(thumbPos:Number):void {}
    
    /**
     *  Sets the size of the thumb button.
     *  
     *  <p>Subclasses should override this method to size 
     *  the thumb button.</p>
     *
     *  @param thembSize The new size of the thumb button.
     */
    protected function sizeThumb(thumbSize:Number):void {}

    /**
     *  Returns the size of the thumb button
     *  given the current range, pageSize, and trackSize settings.
     *  Subclasses should override this to calculate the correct size in
     *  the units of position.
     * 
