Exclusive access to edit rows

I'm developing a program that allows users to view and edit data.



My question:

Is there tools (sql server tools, may be users/roles) to implement the following: There are two users: A and B. User A opened the edit form for row, at this point the user B can not edit the same row.

I know, that i can use colunm for store UserId(user, which edit this row), but this solution is not suitable.