I have a client who has taken over an NEC system,which was already on site.The problem is that at 10.30pm the system switches automatically onto answer phone, and they have to go to the upstairs office in the mornings to turn it off. I would appreciate it anyone could advise me how to turn this feature off. Also what user manuals are required. The only info I can get from the system cover is NEC-IP2AT-924M. Thank You Kevin Ward.