private void RemoveFaculty_Click(object sender, RoutedEventArgs e)
{
int SelectedFacultyId;
SelectedFacultyId = FacultiesGrid.SelectedIndex;
Faculty SelectedFaculty;
SelectedFaculty = (Faculty)FacultiesGrid.Items[SelectedFacultyId];
dbl.RemoveFaculty(SelectedFaculty);
Faculties.Remove(SelectedFaculty);
}