      *  @see mx.core.IViewport
      *  @see mx.core.IViewport#verticalScrollPosition
      *  @see mx.core.IViewport#getVerticalScrollPositionDelta()
+     *  
+     *  @langversion 3.0
+     *  @playerversion Flash 10
+     *  @playerversion AIR 1.5
+     *  @productversion Flex 4
      */
     override public function step(increase:Boolean = true):void
     {

     *  @param localY The Y position relative to the scrollbar control.
     *
     *  @return The position of the thumb button.
     */
    override protected function pointToPosition(localX:Number, 
                                                localY:Number):Number

     * 
     *  @param thumbPos A number representing the new position of the thumb
     *  button in the control.
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10
     *  @playerversion AIR 1.5
     *  @productversion Flex 4
     */
    override protected function positionThumb(thumbPos:Number):void
    {
