private void timer1_Tick(object sender, EventArgs e)
        {
            dt2         = DateTime.Now.ToLongDateString();
            sa2         = DateTime.Now.ToLongTimeString();
            label4.Text = dt2;
            label5.Text = sa2;

            if (dt1 == dt2 && sa1 == sa2)
            {
                Saat nsaat = new Saat();
                timer1.Stop();
                this.Hide();
                nsaat.ShowDialog();
                this.Show();
            }
        }