             return;
 
         var view:ICollectionView = ICollectionView(dataProvider);
-        var sort:Sort = view.sort;
+        var sort:ISort = view.sort;
         if (!sort)
         {
             sortIndex = lastSortIndex = -1;

        }

        column.sortDescending = desc;
        var field:SortField = new SortField(columnName); // name
        field.descending = desc;
        
//        field.name = column.dataField;

        }

        // fields.length == 1, so the collection is sorted on a single field.
        var sortField:ISortField = fields[0];
        var n:int = _columns.length;
        for (var i:int = 0; i < n; i++)
        {
