>I want to make the field readonly so that the foxpro application cannot make any changes to it.
>The bigger problem is that something in the foxpro application is deleting the contents of that field. That field is customer number and it is in the master customers table. The users tell me some of the customer numbers are getting deleted every once in awhile. They say no one is deleting them. I looked through the application code for references to customer number and have not found any spots where it could be getting deleted. So I want to make customer number readonly as a start. Any other ideas you have would be helpful.

I think the initial idea I gave you should work. Make also sure that in all places where you display this field it is displayed in read-only control.

Is it possible that someone changes the tables outside the application? E.g. how secure the database files are?