private void FillData()
        {
            try
            {
                Admins vcontroller = new Admins();
                Entities.hoadon vhoadon = new Entities.hoadon();
                string errMsg = string.Empty;
                vhoadon = vcontroller.getby_hoadon(Request.QueryString["ID"], ref errMsg);
                txttenkhachhang.Text = vhoadon.Tenkhachhang;
                txtdiachi.Text = vhoadon.Diachi;
                txtsdt.Text = vhoadon.Sodienthoai;
                txtemail.Text = vhoadon.Email;
                txtngaydat.Text = vhoadon.Ngaydat.ToString("MM-dd-yyyy");
                txtngaygiao.Text = vhoadon.Ngaygiao.ToString("MM-dd-yyyy");

            }
            catch (Exception ex) { Response.Write(ex.Message); }
        }