//验证是否为正整数

        function isPositiveInteger(s) {

            var re = /^[0-9]+$/;

            return re.test(s);

        }

        if (exchangeCount === "" || exchangeCount === "0" || Number(exchangeCount) === NaN || !isPositiveInteger(exchangeCount))// Number(exchangeCount) === NaN ,如果是非值类型返回值即为NAN

           {

                $("#ValidateExchangeCount").text("请输入正确的换货数量");

                validateResult = false;

            } else 
           {

                $("#ValidateExchangeCount").text("");

            }