There are hundreds of postings about this. Basically, you have to do it one of two ways:
1. If you have a central server-based application (no replicas), then you can create an indexed view based on the number, and simply increment it by 1 each time.
2. But, if you have multiple replicas, there is no way to do this. You should add some sort of prefix based on the user's name (for example 30001WN for me). Then if two people are creating numbers simultaneously, they will still be different.
Automatic number in field (Aage Ytreberg 20.Sep.08)
Feedback response number WEBB7JNS54 created by Watka Naidoo on 09/20/2008
. . has been discussed many times in th... (Watka Naidoo 20.Sep.08)
. . . . Ok! (Aage Ytreberg 20.Sep.08)