I created 4 analog DTS lines that I want to assign to four programmable keys on a 5312. I am able to program 4 button keys on one Extn Directory number but when I want to program the same on the other phones , I have an error message that the Directory number is assigned to another Group. I looked through the Trunk, Hunt, Pickup, Ring Groups but couldn't find any where any of the chosen Directory numbers are members. Any help Please