Subforms in Access 2000

Hi!

I am designing an application where Access 2000 forms are being used as the front end and SQL Server 2000 is being used as the backend.

I have a form which needs to have a subform embedded in it. The main form and subform both have a field INST_SSN on them. When I select INST_SSN on the main form, it needs to display child records corresponding to that on the child form.

INST_SSN is a combo box. If I am using bound forms, I am not able to select any record from INST_SSN. It gives me a msg saying record set is not updatable.

Can I use unbound forms to do the above. Please help. It is really urgent. Any help is really appreciated.

Thanks!