                 var extY:Number = 0;
                 var preferredHeight:Number = layoutElement.getPreferredBoundsHeight();
                 var maxExtent:Number;
+                var availableHeight:Number;
                 
                 var j:int;
                 var rowHeight:Number = 0;

                }
                else
                {
                    // multiple spanning stuff.
                }
            }
        }

    //
    //--------------------------------------------------------------------------
    
    /**
     *  @private
     *  Vectors that keep track of children spanning
     *  content size columns or rows or whether the 
     *  elements don't use columns or rows at all.
     */
    private var colSpanElements:Vector.<ElementConstraintInfo> = null;
    private var rowSpanElements:Vector.<ElementConstraintInfo> = null;
    private var otherElements:Vector.<ElementConstraintInfo> = null;
