Returns the number of time a particular user is logged in the system, 0 is returned if the user is not logged in
NMB_OF_SESSIONS (user)
Cannot be used in the condition of a FIND action.
An instance of an object that belongs to the SystemUser group
Number: how many times the user is logged in, or 0 if not logged in.
IF NMB_OF_SESSIONS(RegularUser) > 1 THEN REPORT ERROR 'User can only be logged in once'