请问关于支付宝API的有关问题。

 /// <summary>        /// 构造提交表单HTML数据        /// </summary>        /// <param name="sParaTemp">请求参数数组</param>        /// <param name="gateway">网关地址</param>        /// <param name="strMethod">提交方式。两个值可选：post、get</param>        /// <param name="strButtonValue">确认按钮显示文字</param>        /// <returns>提交表单HTML文本</returns>        public static string BuildFormHtml(SortedDictionary<string, string> sParaTemp, string gateway, string strMethod, string strButtonValue)        {            //待请求参数数组            Dictionary<string, string> dicPara = new Dictionary<string, string>();            dicPara = BuildRequestPara(sParaTemp);            StringBuilder sbHtml = new StringBuilder();            sbHtml.Append("<form id='alipaysubmit' name='alipaysubmit' action='" + gateway + "_input_charset=" + _input_charset + "' method='" + strMethod.ToLower().Trim() + "'>");            foreach (KeyValuePair<string, string> temp in dicPara)            {                sbHtml.Append("<input type='hidden' name='" + temp.Key + "' value='" + temp.Value + "'/>");            }            //submit按钮控件请不要含有name属性            sbHtml.Append("<input type='submit' value='" + strButtonValue + "' style='display:none;'></form>");            sbHtml.Append("<script>document.forms['alipaysubmit'].submit();</script>");            return sbHtml.ToString();        }