Logic on form not producing correct totals...

[rashar via AccessMonster.com]

Hello,

I have the following form in place:

Quantity_This is a textbox control that allows the user to input a quantity.
ID is a textbox bound to a table ID, Desc and Accessory_Type also bound to a
table. What I want to do is have another textbox on the form to calculate the
values of Quantity_This where Accessory_Type = 20.

Quantity_This ID Desc
Accessory_Type
10 1 DashBoard
7
20 2 Door
20
20 3 Trunk
20

When I use this in my calculated textbox control control source property I
get a value of 50...

=IIf([Accessory_Type]=20 And [ID] Between 2 And 3, Sum([Quantity_This]),
[Quantity_This]*0)

Thanks in advance.