#Error on IIf Statement

[Steven M. Britton]

=IIf(([Billing_UpSell2]=0),Null,[Billing_UpSell2])

this gives me an Error in the field and I don't understand
why. The value comes from a query that is off a table,
the table has the datatype and Number.

 

[Duane Hookom]

You might have left the text box name the same as the field name.