      *  @playerversion AIR 1.5
      *  @productversion Flex 4
      */
-    override protected function viewportResizeHandler(event:ResizeEvent):void
+    override mx_internal function viewportResizeHandler(event:ResizeEvent):void
     {
         if (viewport)
         {

    }

    /**
     *  Set this scrollbar's maximum to the viewport's contentHeight 
     *  less the viewport height. 
     *

     *  @playerversion AIR 1.5
     *  @productversion Flex 4
     */
    override mx_internal function viewportVerticalScrollPositionChangeHandler(event:PropertyChangeEvent):void
    {
        if (viewport)
            value = viewport.verticalScrollPosition;
    }
    
    /**
     *  @private
     *  Set this scrollbar's maximum to the viewport's contentHeight 
     *  less the viewport height and its pageSize to the viewport's height. 
     *  
