private void Button1_Click(object sender, EventArgs e)
{
if (listBox1.SelectedItem != null && listBox2.SelectedItem != null)
{
usersRepository.AttachTeacher(listBox1.SelectedItem.ToString(), gradesRepository.GetSubjectId(listBox2.SelectedItem.ToString()));
listBox1.Items.Clear();
List <Teacher> teachers = usersRepository.GetTeachers(0);
foreach (Teacher teacher in teachers)
{
listBox1.Items.Add(teacher.Name + " " + teacher.Surname);
}
listBox2.Items.Clear();
List <Subject> subjects = gradesRepository.GetSubjects();
foreach (Subject subject in subjects)
{
listBox2.Items.Add(subject.Title);
}
}
}