quote:

---

Two users could be setting the flag to locked at the same time, they would both read the flag as being zeroed, set it then try to update

---

You can update/attempt to update the row in a single statement, then check the result:

update bid_table

    set lock_bit = 1,

        lock_user = @Current_User,

        lock_time = GETDATE()

  where key_field = @Key_Value

        and lock_bit = 0

IF @@ROWCOUNT = 1

  --....Successful

ELSE

  --....Unable to update row (either missing or locked)

-Dan