Thanks for the response Henry.

It is UK postcodes I'm trying to check, I had thought on just reviewing
the column entry instead of validating the code. My lot have a tendenancy
to just use the initial 3 or 4 characters or leaving the entry blank. So
we don't usually see the problem until the mail merged letters have
printed off, usually up to 300 / day

So I suppose what I am trying to do is to flag the fields with the
invalid or missing entries.

Thanks for you help


Mike