Currently I have a MS Access database query that has a field named FedEXDetTotal that totals 9 FedEX charge fields. I have another field that is from our inhouse system called "Total Charge". This is just a normal number field. I have created another Field in this query

Diff: [FedEXDetTotal]-[Total Charge]

This tells me the difference between the Fedex charge and what we actually charged. Everything works OK with this, but when I try to put the criteria >5 for the Diff field, when I run the query, I get a prompt saying "Enter Parameter Value FedEXDetTotal".

Why is Access doing this? How do I get around this? I'm trying to start out with something simple(>5), but what I really want is >[Forms]![Dis].[txtbox_Diff].