Tracy-

>http://accessadvisor.net/doc/03419

Interesting article. Though the complication my particular problem introduced wasn't so much how to generate a key, which is easy enough. The complication is generating a key randomly while making sure other users don't get the key generated whilst the first one is buffered in an edit. Ordinarily, I'd look first to use GUIDs, but since my key is limited all digits and not very long at that, it was a little less obvious how to solve it.

I did end up generating a table of keys in the range I needed, than randomly sorting the list--a twist on David and Sergey's suggestion. I used one digit as a check digit--Gregory's suggestion.

I'll probably consume the keys randomly, too, though that's probably overkill for this. I just don't want the casual bystander to be able to guess what a valid SN is.