function TTimeMarkData.AddTimeValueMark(AItemID: Integer;
  AItemName: String; ATime: TDateTime; AValue: Double): Boolean;
var
  i: Integer;
begin
  Result := False;
  if not FDataSet.Active then Exit;
  if not FDataSet.Locate(F_ITEM_ID, AItemID, []) then
  begin
    FDataSet.Append;
    FItemID.AsInteger  := AItemID;
    FItemName.AsString := AItemName;
    FDataSet.Post;
    Result := True;
  end;
  if ATime <> INVAL_DATE then with FDataSet do
  begin
    Result := False;
    for i := 0 to Fields.Count - 1 do
      if FieldHasTime(Fields[i]) and (GetFieldTime(Fields[i]) = ATime) then
      begin
        NoValidationPost(Fields[i], AValue);
        Result := True;
        Break;
      end;
  end;
end;