>David-
>
>Just to continue thinking out loud...it occurs to me that I can simply grab a lock on the serial number record when I start a transaction, and, if the transaction is cancelled, just release the lock. Otherwise, I'll delete the record. That way I won't throw any numbers away.
>
>Thanks again.


I dont know the type of your SN, but if it's numeric, you can change it to character.
Numeric is base 10 and chars is base 36 (if you use A-Z,0-9).

For a 2 digit len field you have only 100 different SN (10*10) but if you use alpha you have 1296 SN (36*36)!!

For a 7 digit field, numeric give you only 10 000 000 SN and Alpha is 78 364 164 096 SN (around 2 times the Bill Gates fortune, its a big number no?).

:-)