Displaying Data from multilple fields

Hi,

I have a list box which lists part types which is stored in order table

The list box control source is a table that has a unique ID number for
every part, its name and a description of the part

ClosureID NAME DESCRIPTION
X Expanding Panel Panel that grows 150mm
D Passdoor Full Height Passdoor hung
off a jamb or panel

Etc

I made a qry so I could see the Name and Description on a form when a
selection was made from that listbox. My problem is some of the orders
I create dont require a selection from this listbox and when I try to
cycle to the next record I get an error message :

"The Microsoft Jet database engine could not find a record in
tblClosures with key matching felds "tblOWDetails.Closure ID"

Sometimes I dont have to make a selection but if I dont I get this
error.

Can anyone help

Thanks

Blunka