Mailmerge Problem

I am looking for a app that perform multiple record mailmerge similar to Microsoft Office words. I product sample demo I saw only one record is mailmerged although in the code is seem it was set for multiple record. code: for (int i = 0; i < 50; i ) { dt.Rows.Add(1000 i, GetRandomCompanyName(), GetRandomName(), GetRandomAddress(), GetRandonCity(), GetRandomPostalCode(), GetRandomCountry()); }