Hi,
Oopps. hehe.. sorry.. tahnk you for your reply.
Hmm.. Actually I post this question before, However I would liek to get more ideas..
I have two classes, license manager and adminshutdown (as shown in FP Advisor on June 2001 issue). Both using seperate array to store the each instance. It will loop through the array and call method of the instance stored to perform process.
Once my client application startup, it will crateobject of my license manager and login, and logout if terminated. On the other hand, I have a small application in server that allow admin to get the list of "active" workstation that login to system. If necessary, admin may ask all workstation to terminate application for database update and etc. Once application teminated but adminshutdown, the logout method have to be called too.
In OO design, i heard that one class should only do one job. So, in the case above, how to design the interface in order license.logout() will be called if adminshutdown.shutdown being called()? and also if I have more services it should not effect my whole design.

Thank you