>My perspective was never from VFP's side but SQL Server's, using triggers, that's why I was asking whether to use SQL logins or Windows users. Now I see that the way you do it makes it much more easy to develop it. Thank you very much!

Are you asking if you should be using SQL Authentication or Windows Authentication in MS-SQL? If so, then the preferred method would be to use Windows Authentication. SQL Server Authentication doesn't work unless you enable it by selecting Mixed Mode Authentication when you install MS-SQL.