One of the interesting things you learn is never to use the record number for anything useful. It can change over time and upset the maintainer of the database.
Instead, make the field requirement be "unique" to disallow duplicates. You can prefill it with a command of recno()+1 with a command (your work) to get it started and add code to find the max number of the existing records and add 1 when you add a new record.
I have a database for tracking new/old requirements for systems development. In the past these were tracked via notepad, excel, word by a number of people and our requirement numbers varied and was very confusing for our developers. What I did was create a access DB with one of the fields labeled requirement number and in this field I'm listing all of the old requirements using whatever number they originally had. Now going forward when adding a new requirement I want this number to auto-populate with the next higher number, last record + 1 kind of thing. I can't use auto-number with the existing field and I don?t want a new field with auto-number because it would start at #1 all over again.
The question is how can I make the default value of my field be last record number + 1?