private void TheoMaGV_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            check = 5;

            this.pnNhapTT.Enabled    = true;
            this.txtTaiKhoan.Enabled = false;
            this.txtMatKhau.Enabled  = false;
            this.cbbLoaiTK.Enabled   = false;
            this.txtMa.Enabled       = true;

            this.txtMa.ResetText();

            this.btnThucThi.Enabled = true;
            this.btnHuyBo.Enabled   = true;

            this.btnThem.Enabled = false;
            this.btnSua.Enabled  = false;
            this.btnXoa.Enabled  = false;
            this.btnTim.Enabled  = false;

            this.txtMa.AutoCompleteMode   = AutoCompleteMode.Suggest;
            this.txtMa.AutoCompleteSource = AutoCompleteSource.CustomSource;

            var lstGV = gvBUS.getMaGV();
            var lstSV = svBUS.getMSSV();

            AutoCompleteStringCollection AutoComp = new AutoCompleteStringCollection();

            foreach (var gv in lstGV)
            {
                AutoComp.Add(gv.MaGV);
            }
            foreach (var sv in lstSV)
            {
                AutoComp.Add(sv.MaSV);
            }

            this.txtMa.AutoCompleteCustomSource = AutoComp;

            this.txtMa.Focus();
        }