Prohibiting modification of a field once it's had a value assigned
Is there a way in Filemaker 8 to set up a field so that once a value has been entered, it can't be changed again? I have a simple database that young students are using. I want them to be able to enter new records and have access to all the fields, but they often wind up accidentally changing the information on an old record instead of creating a new one. They think everything is fine because when they're done they see a record just the way they want it and don't realize they have just messed up a record that was already in the database.