Should have added that we use regular Program Neighbourhood ICA clients v. 7.1. No PN Agent or web clients in use. -----Original Message----- From: Steve Parr Sent: Tuesday, February 14, 2006 4:45 PM To: 'thin@xxxxxxxxxxxxx' Subject: Looking for ways to verify an Active Directory user and password to access app running on Citrix which at the moment uses it's own internal authentication One of the developers in our IT group is currently looking for ways to verify an Active Directory user and password from within one of the applications running here. He has found a way to do this using the LogonUser API call. However, while this method works when connected to any computer using RDP, this method always fails when connected to a Citrix server. Without having to consult the Citrix SDK as we do not have a copy does anyone know what API\dll's will do the trick if we are running Mteaframe XP FR3? Steve Parr Metroland Printing, Publishing and Distributing Ltd.