protected virtual void TimeBetweenClassses_button_Click(object sender, EventArgs e)
        {
            NewMinTimeBetweenClasses_Form form = new NewMinTimeBetweenClasses_Form(ref
                                                                                   this.emp);

            this.Hide();
            form.FormClosed += new FormClosedEventHandler(FormClosedHandling);
            form.ShowDialog();
        }
        protected override void TimeBetweenClassses_button_Click(object sender, EventArgs e)
        {
            EmpInterface emp = this.lecturer;
            NewMinTimeBetweenClasses_Form form = new NewMinTimeBetweenClasses_Form(ref emp);

            this.Hide();
            form.FormClosed += new FormClosedEventHandler(FormClosedHandling);
            form.ShowDialog();
        }