private void btnOK_Click(object sender, EventArgs e)
        {
            string cashier_name = cmbUsername.Text.Trim();
            string password     = txtPassword.Text.Trim();

            if (password == "")
            {
                lblMsg.Text    = "密码不能为空";
                lblMsg.Visible = true;
                return;
            }
            CashierBLL cb  = new CashierBLL();
            string     xml = cb.cashierLogin(cashier_name, password);

            try
            {
                string is_success = XMLStrHelper.GetXmlNodeByXpath(xml, "Alipay/is_success").InnerText;

                if (is_success == "T")
                {
                    CashierBLL cashierBll = new CashierBLL();
                    StaticData.Cashier.cashier_id   = XMLStrHelper.GetXmlNodeByXpath(xml, "Alipay/cashier_id").InnerText;
                    StaticData.Cashier.cashier_no   = XMLStrHelper.GetXmlNodeByXpath(xml, "Alipay/cashier_no").InnerText;
                    StaticData.Cashier.cashier_name = cmbUsername.Text;
                    cashierBll.setConfig(StaticData.Cashier);

                    lblMsg.Text    = "登录成功";
                    lblMsg.Visible = true;

                    this.DialogResult = DialogResult.OK;
                    this.Close();
                }
                else if (is_success == "F")
                {
                    string error_msg = XMLStrHelper.GetXmlNodeByXpath(xml, "Alipay/error_msg").InnerText;
                    lblMsg.Text    = error_msg;
                    lblMsg.Visible = true;
                }
                else
                {
                    string error_msg = XMLStrHelper.GetXmlNodeByXpath(xml, "Alipay/error_msg").InnerText;
                    lblMsg.Text    = error_msg;
                    lblMsg.Visible = true;
                }
            }
            catch (Exception ex)
            {
                lblMsg.Text    = "异常:" + ex.Message;
                lblMsg.Visible = true;
            }
        }