Paul, the problem is that if the first worker has a datapage open and pulls a number, while they are doing so there is nothing to stop a second worker opening the datapage and also pulling the same number because at that point nothing has been saved. Unfortunately Caspio doesn't lock that first number while it is being used and it only becomes unavailable after the record is saved. I raised this a while back when I developed a database for survey bookings and, like you, discovered that two call centre workers had the same slot (record) open, the first one saved it only to have it over-written by the next when they saved "their" record. It was rare fortunately but very frustrating because there was nothing to indicate that a record had been over-written and the first data was lost. I still haven't come up with a satisfactory solution.