做过工行接口的都进来看看吧,该怎么解决

做过工行接口的都进来看看吧
StringBuilder strSet = new StringBuilder();
            strSet.Append("<?xml version=\"1.0\" encoding=\"GBK\" standalone=\"no\"?>");
            strSet.Append("<B2CReq>");
            strSet.Append("<interfaceName>ICBC_PERBANK_B2C</interfaceName>");
            strSet.Append("<interfaceVersion>1.0.0.14</interfaceVersion>");
            strSet.Append("<orderInfo>");
            strSet.Append("<orderDate>20120715154033</orderDate>");
            strSet.Append("<curType>001</curType>");//支付币种
            strSet.Append("<merID>0409EC23772721</merID>");//商户代码
            strSet.Append("<subOrderInfoList>");
            strSet.Append("<subOrderInfo>");
            strSet.Append("<orderid>123123123</orderid>");//订单号
            strSet.Append("<amount>1</amount>");   //数值
            strSet.Append("<installmentTimes>1</installmentTimes>");//分期付款期数    
            strSet.Append("<merAcct>0409001219300035126</merAcct>");//商户账号
            strSet.Append("<goodsID>001</goodsID>");//商品编号
            strSet.Append("<goodsName>123123</goodsName>");//商品名称
            strSet.Append("<goodsNum>1</goodsNum>");//商品数量
            strSet.Append("<carriageAmt>0</carriageAmt>");//已含运费金额
            strSet.Append("</subOrderInfo>");
            strSet.Append("</subOrderInfoList>");
            strSet.Append("</orderInfo>");
            strSet.Append("<custom>");
            strSet.Append("<verifyJoinFlag>0</verifyJoinFlag>");//检验联名标志
            strSet.Append("<Language>ZH_CN</Language>");//语言版本
            strSet.Append("<HangSupportFlag>1</HangSupportFlag><HangTimeInterval>24</HangTimeInterval>");
            strSet.Append("</custom>");
            strSet.Append("<message>");
            strSet.Append("<creditType>2</creditType>");//支持订单支付的银行卡种类    
            strSet.Append("<notifyType>HS</notifyType>");
            strSet.Append("<resultType>1</resultType>");//结果发送类型
            strSet.Append("<merReference>http://localhost:80/Default.aspx</merReference>");//商户reference
            strSet.Append("<merCustomIp>172.28.69.45</merCustomIp>");//客户端IP
            strSet.Append("<goodsType>1</goodsType>");//虚拟商品/实    
            strSet.Append("<merCustomID>111</merCustomID>");//买家用户号    
            strSet.Append("<merCustomPhone>12312312311</merCustomPhone>");//买家联系电话    
            strSet.Append("<goodsAddress>ad</goodsAddress>");//收货地址    
            strSet.Append("<merOrderRemark>12313</merOrderRemark>");//订单备注    
            strSet.Append("<merHint></merHint>");//商城提示    
            strSet.Append("<remark1></remark1>");
            strSet.Append("<remark2></remark2>");
            strSet.Append("<merURL>http://localhost:80/Default.aspx</merURL>");
            strSet.Append("<merVAR>test</merVAR>");