Issue in Grid

Hi All,
I have a grid by name Master which has two feild Name,Address (Note:It is Master Table)
I have another grid by name Slave which has four feild  Name,Address,phoneNo,pinNo.My issue is i want to display the data of master (Name,Address) in slave(Name,Address) the other two coloumn of slave(PhoneNo,pinNo) is to filled by enduser and it has to be saved .I am fresher looking out for solution from past 3 days,please do send me the code with explanation.please help me,Thanks in Advance
Thanks
Tannu