I checked the 'unique value' under validation tab to prevent user from recreating duplicates, but i believe the error buttons (Revert, Yes, No) that appear when validationg fails are very unuser-friendly. Some of the users are limited to be unable to delete or edit records, only add. I can education them, but accord to murphy's law; "Whatever can go wrong, will go wrong"

Thus is there any calc that can be use to mimic this function?

FileMaker really could use a "Unique( FieldName ; TableName )" function -- hint hint to those that don't read the forums

On that topic, can't really be helped, unless you MAYBE stored those values in a related table and then using some sort of plugin executed a script that uses the IsEmpty( relatedtable ) function (related via a global that gets set) and then act on the results of that. Kind of annoying, but if you can work it out... yay.

Plug-in that might help: DoScript by myFM Butler -- Freeware

That will be way cool right? Doesn't sound like a complicating function for them to add in anyway.