private void cmbUniversity_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
cmbDepartment.IsEnabled = false;
ComboBoxLogic comboboxLogic = new ComboBoxLogic();
ComboBoxModel sel = (ComboBoxModel)cmbUniversity.SelectedItem;
cmbFaculty.IsEnabled = true;
if (sel != null) cmbFaculty.ItemsSource = comboboxLogic.Faculties(sel.id);
cmbFaculty.DataContext = EditData;
cmbDepartment.ItemsSource = null;
cmbDepartment.IsEnabled = false;
}
