type
  TDataRecord = array of record
    FieldName: string;
    Value: Variant;
  end;
 
type
  TForm1 = class(TForm)
    ... 
  private
    FInitRecord,FPostRecord: TDataRecord;
  end;
 
function GetDataRecord(DataSet: TDataSet): TDataRecord;
var
  I: Integer;
begin
  Result := nil;
  if Assigned(DataSet) then begin
    SetLength(Result,DataSet.FieldCount);
    for I := 0 to DataSet.FieldCount - 1 do begin
      Result[I].FieldName := DataSet.Fields[I].FieldName;
      Result[I].Value := DataSet.Fields[I].Value;
    end;
  end;
end;
 
type
  TDataSetAccess = class(TDataSet);
 
procedure TForm1.ADODataSet1AfterInsert(DataSet: TDataSet);
begin
  // set initial values 
  ADODataSet1.FieldByName('PK').Value := GetMyPKValue;
  ADODataSet1.FieldByName('DateCreated').AsDateTime := Now(); 
  // un-modify
  TDataSetAccess(ADODataSet1).SetModified(False);
  // save initial record
  FInitRecord := GetDataRecord(ADODataSet1);
end;    
 
procedure TForm1.ADODataSet1BeforePost(DataSet: TDataSet);
var
  I: Integer;
begin
  if ADODataSet1.Modified then
  begin
    FPostRecord := GetDataRecord(ADODataSet1);
    Memo1.Lines.Clear;
    for I := 0 to Length(FPostRecord) - 1 do begin
      if FPostRecord[I].Value <> FInitRecord[I].Value then
        Memo1.Lines.Add(Format('Field %s was modified',[FPostRecord[I].FieldName]));
    end;
  end;
end;