private void GetSelectedHospitalExpertiseDoctors() { if (listBoxControlHospital.SelectedItem != null && listBoxControlExpertise.SelectedItem != null) { doctors = bllMember.GetSelectedHospitalExpertiseDoctors((Hospital)listBoxControlHospital.SelectedItem, (DoctorEnumExpertise)listBoxControlExpertise.SelectedItem, member); } else { doctors.Clear(); } }