private void CmbFaculty_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
cmbDepartment.ItemsSource = null;
ComboBoxLogic comboboxLogic = new ComboBoxLogic();
ComboBoxModel sel = (ComboBoxModel)cmbFaculty.SelectedItem;
cmbDepartment.IsEnabled = true;
if (sel != null)
{
cmbDepartment.ItemsSource = comboboxLogic.Department(sel.id);
}
}
