filter via dropdown

[Russ]

I have a form called "New_Patient_Entry_Form" which is built on a table
called Demogrpahics. This has fields SSN (primary key), LastName, FirstName,
an Sex.

There is a subform inside of this form based on a table called "New_Visit"
which has fields of SSN (primary key), DateofVisit (primary key), and other
fields. the sql of the subform is

SELECT New_Visit.LastName AS Expr1, New_Visit.SSN, New_Visit.DateOfVisit,
New_Visit.VisitLocERClinicFloorECF, New_Visit.Side, New_Visit.Location,
New_Visit.Joint, New_Visit.TypeOfInjury, New_Visit.TimePain,
New_Visit.Pain_DWMY
FROM New_Visit
ORDER BY New_Visit.DateOfVisit DESC;

the two tables are connected by a one to many relationship with demographics
being on teh one end of the relationship.

my current set allows for me to select apatient and then scroll between teh
different visits that are present in new visit.

i want to make DateofVisit a drop down list showing hte different records in
New_Visit table for that patient, and the one i select will come up. also,
there needs to be an option to add a new record with the curent date and time
being the default for the DateofVisit.

thank you for your help,
russ