      *  Returns the amount one would have to add to the viewport's current 
      *  verticalScrollPosition to scroll by the requested "scrolling" unit.
      * 
-     *  The value of unit must be one of the following flash.ui.Keyboard
-     *  constants: UP, DOWN, PAGE_UP, PAGE_DOWN, HOME, END.
+     *  The value of unit must be one of the following mx.core.ScrollUnit
+     *  constants: LEFT, RIGHT, PAGE_LEFT, PAGE_RIGHT, HOME, END.
      * 
-     *  To scroll by a single row use UP or DOWN and to scroll to the
-     *  first or last row, use HOME or END.
+     *  To scroll by a single column use LEFT or RIGHT and to scroll to the
+     *  first or last column, use HOME or END.
+     * 
+     *  @see ScrollUnit
      */
     function getVerticalScrollPositionDelta(unit:ScrollUnit):Number
      

     *  Returns the amount one would have to add to the viewport's current 
     *  verticalScrollPosition to scroll by the requested "scrolling" unit.
     * 
     *  The value of unit must be one of the following flash.ui.Keyboard
     *  constants: UP, DOWN, PAGE_UP, PAGE_DOWN, HOME, END.
     * 
     *  To scroll by a single row use UP or DOWN and to scroll to the
     *  first or last row, use HOME or END.
     */
    function getHorizontalScrollPositionDelta(unit:ScrollUnit):Number
    

     */
    function get contentHeight():Number;

    /**
     *  The X coordinate of the origin of the region the target is
     *  scrolled to.  
     * 
     *  If clipContent is true, setting this property typically causes 
     *  <code>scrollRect</code> to be set to:
     *  <pre>
     *  new Rectangle(horizontalScrollPosition, verticalScrollPosition, width, height)
     *  </pre>
     * 
     *  Implementations of this property must be Bindable and
     *  they must generate events of type "propertyChange".
