public void LayDS_QuyenDN()
 {
     dt = tk.Lay_DS_QuyenDN();
     cbb_QuyenDN.DataSource    = dt;
     cbb_QuyenDN.DisplayMember = "TenQuyenDN";
     cbb_QuyenDN.ValueMember   = "QuyenDN";
     if (cbb_QuyenDN.Items.Count > 0)
     {
         cbb_QuyenDN.SelectedIndex = 0;
     }
 }
        public void Hien_Quyen()
        {
            DataTable dt_qdn = tk.Lay_DS_QuyenDN();

            cbb_QuyenDN.DataSource    = dt_qdn;
            cbb_QuyenDN.DisplayMember = "TenQuyenDN";
            cbb_QuyenDN.ValueMember   = "QuyenDN";
            if (cbb_QuyenDN.Items.Count > 0)
            {
                cbb_QuyenDN.SelectedIndex = 0;
            }
        }