         var columnName:String = event.dataField;
         var columnNumber:int  = event.columnIndex;
         var sortFields:Array;
-        var sort:Sort;
+        var sort:ISort;
 
         if (!sortableColumns || !columns[columnNumber].sortable)
             return;

            return;

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

        }

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