Access 2002. In a Customer's table, I have separate FirstName and LastName fields. The form's Record Source is a query based on the Customer's table. At the form or query level, I also display the first-last names concatenated. I need to ensure, using code, that the FirstName-LastName, when concatenated, cannot be entered into the table's parsed fields more than once (not duplicated). How do I do this? I have code that works on the pre-concatenated, individual fields in the Before Update property of the FirstName and/or LastName controls of the form, but what is the code that will work on the concatenated field itself (FullName: [FirstName]&" "&[LastName])? I tried the same code on the concatenated field and it did nothing. Thank-you 
