Mark record as Edited

[ggedal]

SmartGWT 2.2 and Firefox 6.3.12
I need to edit a record not available in grid with groups because row is not visible when group is collapsed, so I am using following code:

RecordList recordList = grid.getOriginalRecordList();// this return original data with no grouping
int rows = recordList.getLength();
for (int i=0; i<rows; i++) {
   ...
  record.setAttribute("amount",  Float.toString(newValue));
}

The problem is that during update the record is not marked as edited and is not updated. Please let me know how to mark this record as edited.
Thanks.