private void NViewLeaveBtn_Click(object sender, EventArgs e)
        {
            timetableview openForm = new timetableview();

            this.Hide();
            openForm.ShowDialog();
        }
        private void PictureBox5_Click(object sender, EventArgs e)
        {
            timetableview openForm = new timetableview();

            this.Hide();
            openForm.ShowDialog();
        }