private void btThem_Click(object sender, EventArgs e)
        {
            FormThemDoan formThemDoan = new FormThemDoan();

            formThemDoan.ShowDialog();
            loadDSDoanDL();
        }
 private void btSua_Click(object sender, EventArgs e)
 {
     if (curDoanDL != null)
     {
         FormThemDoan formThemDoan = new FormThemDoan(curDoanDL);
         formThemDoan.ShowDialog();
         loadDSDoanDL();
     }
 }