Just a thought from a rattled brain but...

If you dont need to see the previous days balance prior to doing an insert or update, then why not just throw a...

Ive used the following to retrieve the table name;

declare @TbleName nvarchar(324)

SET @TbleName=(Select name from sysobjects where sysobjects.id = (select parent_obj from sysobjects where sysobjects.id =@@PROCID))

Of course then what you do...