      *  @see mx.components.baseClasses.FxTrackBase#setValue()
      *  @see mx.core.IViewport
      *  @see mx.core.IViewport#horizontalScrollPosition
-     *  @see mx.core.IViewport#horizontalScrollPositionDelta()
+     *  @see mx.core.IViewport#getHorizontalScrollPositionDelta()
      */
     override public function page(increase:Boolean = true):void
     {
         if (!viewport)
             super.page(increase);
         else
-            updateViewportHSP((increase) ? Keyboard.PAGE_DOWN : Keyboard.PAGE_UP);
+            updateViewportHSP((increase) ? ScrollUnit.PAGE_RIGHT : ScrollUnit.PAGE_LEFT);
     }
     
     /**

     *
     *  @private
     */
    private function updateViewportHSP(unit:uint):void
    {
        var delta:Number = viewport.horizontalScrollPositionDelta(unit);
        setValue(viewport.horizontalScrollPosition + delta);
    }
    

     *  @see mx.components.baseClasses.FxTrackBase#setValue()
     *  @see mx.core.IViewport
     *  @see mx.core.IViewport#horizontalScrollPosition
     *  @see mx.core.IViewport#getHorizontalScrollPositionDelta()
     */
    override public function step(increase:Boolean = true):void
    {
        if (!viewport)
            super.step(increase);
        else
            updateViewportHSP((increase) ? ScrollUnit.RIGHT : ScrollUnit.LEFT);
    }   
    
    /**
