private void btnNextSoal_Click(object sender, EventArgs e)
        {
            Menu3_4 menu33 = new Menu3_4();

            this.Hide();
            DialogResult result = menu33.ShowDialog();
        }
 private void btnback_Click(object sender, EventArgs e)
 {
     this.Hide();
     Menu3_4      menu34  = new Menu3_4();
     DialogResult results = menu34.ShowDialog();
 }