Hi.
I use following technique in VFP to lock a file/record:
(I want to ensure nobody else grabs a balance and updates it while I am doing something with the balance
(Have not included error checking etc)

Do while .t.
If Flock('MYALIAS')
X=MyAlias.Balance
Do Stuff (e.g. Get data from other tables)
Replace MyAlias.balance with MyNewBalance
UnLOCK
EXIT
Else
Wait window 'File in Use..Please wait' Nowait
Endif
Enddo

How ould I do this in C#, SQL Server ?

TIA
Regards,
Gerard