I'm trying to figure out how to prevent data entry in a sub-form where Date, Time, and Doctor already exists.
The user tries to select a Doctor from a combobox and if that combination already exists give the user a warning message that they have already scheduled that doctor for that date and time.
The field names are Date, Time, and Doctor. The table the subform is bound to is tblPotenialAppointmentDatesAndTimes. The field names in the table are AppointmentDate, AppointmentTime, and DoctorName. Can someone help?