Thanks Guys ,I wasn't too clear in my question but you gave me the answer and I have a happy customer ,,what he wants is when he is talking on eg. line one and a call is ringing on line two ,he wanted to see who it is without interrupting his first call ,so I just gave him a memory btn with 811 on it and he just presses it and line two with no problem and sees the second caller with no interruption to his first call. thanks again