Help with a field calculation?

[Key]

I have a database that contains a field that is restricted to exactly 17 characters. There now is a requirement for it to be restricted to either 17 or 18 characters.

How do I do this?

Thanks a lot for any help...

[-Queue-]

You can validate by Length(field) = 17 or Length(field) = 18.

[Key]

Wow. How simple was that? Thanks for the quick response!