Selection in Combo Box to set Yes/No in a Table?

[alpinegroove]

I have form (linked to tblCourses) and a subform (linked to tblPeopleCoursesRoles--a junction table).

In the subform, users designate the person associated with the course and his/her role in the course (Instructor, TA, or Reader).

Can the following be automated?

tblCourses has a Yes/No field called "CourseHasTA."

If a user selects role "TA" in the subform, can the Yes/No field "CourseHasTA" be set automatically to Yes?

Thank you!

[June7]

This would require VBA code. But why - determining this status can always be accomplished with query or DLookup.