Apologies if this is a silly question...

I have a job number field which is set to serially increment each time a user sets up a new record. Users cannot delete a record. But I'm getting a few missing records in the sequence (which is a major problem because my Filemaker database has to link up and correspond with another database).

I think this is happening because User A starts entering a new record, while this is happening User B enters a new record... and then occasionally User A abandons setting up a new record for whatever reason, leaving one missing number in the sequence.

Any thoughts on the best way to prevent this from happening?

Try changing the serial number to generate on commit, rather than on creation.

Another option is to have users fill out a "scratch record" using global fields only. When ready, they can call a script that creates a new record and fills out the 'real' fields.

Thanks very much, I feel I should have worked out the first option myself... with hindsight its staring me in the face when you define the field!!!