A customer has 3 users that make sale invoices. They are all on 3 different locations.

In Accountability, the periods are monthly. Let's say we are the 1th of February, a new period
1/ it happens almost monthly that at start of new period (month), they still need to book invoices on the previous period (month)
2/ as long as an new invoice is NOT book yet in the new period, the user needs to get an alert that points to the still open previous period AND ask confirmation if (s)he is sure to start a first booking in new period
3/ when a new invoice is booked in the new period, they can't book a next invoice in the previous period (january).

This is needed as there are 3 people booking sale invoices, ánd they are not in the same office. As such they get a warning to be sure to check with each other if someone still need to book in the previous period before going ahead in the new period.