period according to the method a validity parameter associated with the user data is decreased on the basis of elapsed time and or the number of log on times and or the weighting values of the commands entered application_number US 98269701 A description the system illustrated in fig1 comprises a first switching center 16 a a second switching center 16 b and a third switching center 16 c the switching centers 16 a 16 b and 16 c are connected to each other via a telecommunication network 17 the telecommunication network 17 is e g an isdn network isdn integrated services digital network the system illustrated in the figure additionally comprises a workstation 15 which is connected to the first switching center 16 a the first switching center 16 a can be controlled by means of the workstation 15 in addition it is possible to establish a remote connection from the workstation 14 to switching centers 16 b and 16 c via the telecommunication network 17 an essential part comprised in each switching center is a software block 15 forming part of the operating system of the telephone switching system the system presented in fig2 comprises a telephone switching center 16 the switching center 16 comprises a software block 15 which is part of the operating system of the telephone switching system the system also comprises a workstation 14 the software block 15 comprises a mmi man machine interface management block 9 which acts as a software block controlling the functions of the system these functions include the transmission of information between the workstation 14 and the switching system the software block 15 comprises an author mml block 10 a user management block 11 a profiles file 12 and a passwords file 13 the user interface is implemented by.