Date controlled billing
I'm using Filemaker pro 11 to create a database that holds details of clients monthly payments on 12 month contracts. Clients have the option of paying uprfont or paying monthly via direct debit. On their file i want there to be a field called 'Paid', with two possible answers "Yes" or "No." I want the 'Paid' field on the first of every month to revert back to "No" across the board except for those clients that have paid upfront. This would indicate that they need to be debited for this month. To indicate that a client has paid upfront I have another field called 'Payment Upfront' with two possible answers "Yes" and "No" again. Can someone please help me to construct the if statement or script that will accomplish this?
Any help would be much appreciated!