[@LockOwner =] 'lock_owner' Is the lock owner. lock_owner is nvarchar(32) and can be Transaction (the default), or Session. When the lock_owner value is the default, or when Transaction is specified explicitly, sp_getapplock must be executed from within a transaction.http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_sp_ga-gz_5gh5.asp