If I understand you correctly, you would like to be able to select unique classes within your registration form based on your query results. One way to do this is to change your query to a make table query. After access (run query) has successfully created your table using your query criteria, then create a combo box field within the registration form(s). Use the newly created table as the control source for your combo box. You can also enable the 'limit to list=yes' property, so people can only select classes within your drop down list. This is really important for quality assurance and reporting purposes. Hope this helps.