     }
     
    /**
-    *  Called when the viewport's contentWidth changes, does nothing by default.
+    *  Called when the viewport's <code>contentWidth</code> value changes. Does nothing by default.
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10

    }

    /**
     *  Calculate the size for the thumb from the current range, pageSize, and
     *  trackSize settings.
     * 
     *  If fixedThumbSize is true, then subclasses should return a value based
     *  on the thumb's preferred size instead.
     * 
     *  @see fixedThumbSize
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10

    }
    
    /**
     *  Handles releasing the increment or decrement button of the scrollbar. 
     *  This ends the stepping operation started by the original buttonDown
     *  event on the button.
     *
     *  @see spark.components.Button
     *
     *  @langversion 3.0
     *  @playerversion Flash 10
     *  @playerversion AIR 1.5
     *  @productversion Flex 4  
     
     */
    protected function button_buttonUpHandler(event:Event):void
    {
