protected virtual void CourseToTeach_button_Click(object sender, EventArgs e)
        {
            ChooseCoursesToTeach form;

            if (teachingAssist != null)
            {
                form = new ChooseCoursesToTeach(teachingAssist.CoursesToTeach, ref emp);
            }
            else
            {
                form = new ChooseCoursesToTeach(null, ref emp);
            }
            this.Hide();
            form.FormClosed += new FormClosedEventHandler(FormClosedHandling);
            form.ShowDialog();
        }
        protected override void CourseToTeach_button_Click(object sender, EventArgs e)
        {
            EmpInterface         emp = this.lecturer;
            ChooseCoursesToTeach form;

            if (lecturer != null)
            {
                form = new ChooseCoursesToTeach(lecturer.CoursesToTeach, ref emp);
            }
            else
            {
                form = new ChooseCoursesToTeach(null, ref emp);
            }
            this.Hide();
            form.FormClosed += new FormClosedEventHandler(FormClosedHandling);
            form.ShowDialog();
        }