private void ChonTuDien_NhoNhanhButton_Click(object sender, EventArgs e)
 {
     ChonTuDien1 ctd = new ChonTuDien1(NguoiDung);
     if (ctd.ShowDialog() == DialogResult.OK)
     {
         int[] tudien = ctd._TuDien;
         tuvunglambantest = ctd.tuvunglambantest;
         //Clear Control
         foreach (Control ct in DeBai_NhoNhanhLayout.Controls)
         {
             ct.Text = "";
         }
     }
 }
/// <summary>
/// ////////////////////////////////Xử lý ô chữ////////////////////////////////////*
/// </summary>

        private void ChonTuDien_OChuButton_Click(object sender, EventArgs e)
        {
            ChonTuDien1 ctd = new ChonTuDien1(NguoiDung);
            if (ctd.ShowDialog() == DialogResult.OK)
            {
                int[] tudien = ctd._TuDien;
                tuvunglambantest = ctd.tuvunglambantest;
            }
        }