Not exactly sure why you would want to do that.
The other option is ti use a stored procedure to do it automatically for you.
Ya, ya, that's what everyone says. "Why would you want to do that?"
This is a give-away system that creates a print out with a non unique number associated with it. That number is used to schedule the give-away in a paper log. Although the serial number is non unique, the give-aways are infrequent enough that no two live give-aways will have the same number.
What it really boils down to is the end users are use to using non unique serial numbers between 1 and 150.
This reminds me of something I heard in a programming class once:
It is easier to change the specification to fit the program than vice versa ;).
Thanks for the info on stored procedures, I was unaware of them. I'm pretty new to SQL so that looks like a great place to start learning.