I have a CM 5.1 with the Receptionist phone being a 7960 with 6 lines. Sharing the same lines are a 7921. When the call is answered on a 7921 phone and if another call comes in, the call goes to the 2nd line. The problem we are having, is that if the receptionist is tending to the first call, she doesnt know the 2nd call came in. Is there a way we can have that phone ring it another call is coming in on that phone?