Thanks MrHappy, thanks very much for the answer. When I press D I am asked to enter my own code and when I do so I get the following options - operate user outputs, change code, review logs, walk test, siren test, dial out menu and allow engineer menu. Separately, if I enter the engineer code I get other options as well - but none of these have the ability to add or edit users. Are you saying that there is a different code that is the system master code - which is different than my personal code and the engineer code - that would allow me to add/edit users so I need to try to find out what that is and to enter that when asked to enter a code when pressing D? I think the system master code is 2222 by default but that does not work. Thanks for advising and, again, I appreciate the help!