user profiles

[Alan Maciel]

I need 3 user accounts, one needed for the production site, the other for the support department so the users logins will be:   'production' and 'support'   I created with adduser <name> and I set them the password with passwd <name>   I need this users accounts  with root privileges, so I think that if I give the root password to this users they can use the 'su' command to do all their admin tasks, but how do I prevent this users so they don't log in as 'root' in the login screen directly only with the 'su' command?