Duane, thanks a lot for trying to help.

My form is named "frm_G" and the NAME propertyof the listbox is
"Genotype". So, in the query criterion under the Genome field I typed

Forms!frmfrm_G!lboGenotype!

I have the form open and then I run the query. All I get is a box
labeled "Enter parameter value" with a single window above which is
Forms!frmfrm_G!lboGenotype!

Of course I want it to display the form with the listbox so I can select
Genotype.

Can you tell where I've gone wrong?

Thanks again, Rob

Duane Hookom wrote:

You would set the criteria of the "Genotype" field to:
Forms!frmMyForm!lboGenotype
Substitute your form and control name and make sure the form is open when
you run the report/query.