I have a related file that is supposed to give each new record a serial number, incremented by 1 from the previous record, whenever the record is created. I discovered that some records were being overwritten when new records were created. When I checked my field definition for the serial number I found the the serial number seemed to revert to a previous number. For examlpe, instead of reading "1200" as the next number, it read "680". This caused records to share the same serial number. My solution was to Check off the "prevent user modification" My question: Is there a bug in filemaker5 that may allow a serialized number to revert back to a previous number? I used this solution with FM4 and never had this problem.

Thanks

Describe in detail how the serial number is being generated.

*All* of my serial number fields have "prevent modification od value" checked, no exceptions.

The field is a number field that has auto enter serial number. I did not have the prevent modification number checked before. Now I do. I wonder how important that is.

You don't have to wonder any more, now you know how important it is. ;-)

But seriously, what could have been changing the serial numbers? Users... a script... ?

I've found a common source of errors like this (and I've done it myself) is performing a find, typing the number into the field and clicking on the find button... only to realise that I'm still in browse mode and that I've just typed over some important information in the current record.

The "Prohibit modification of value" option prevents these errors from happening. And in a relational database the integrity of the match fields is *really* important. As you've discovered.

[This message has been edited by Vaughan (edited December 13, 2000).]