I get #Error in Access Report. from Expr =[Price]*[Quantity] Why?

[Linjet]

In entered Expression =[Price}*Quantity to multiply the Price x Qty to get
a total for each line item. I received no error message in Design View. When
I go to Rpt Preview, I get instead of (total per line item) #Error. I am
using Acces 2002. Why?
The rest of the expresions: Total per Customer Order and Discount Amount work.
The Qtys and The Prices show up correctly.

 

[Allen Browne]

What is the Name of this text box?

Access gets confused if it has the same name as one of the fields, but is
bound to something else. For example, it must not be called Price or
Quantity.