Jquery-ajax()方法提交json数据

var strJson = getStrPayJson();
            $.ajax({
                type: "POST",
                url: "/usercenter/paycoupon",
                contentType: "application/json",
                dataType: "json",
                data: JSON.stringify({
                    "payUsers": strJson
                }),
                success: function (jsonResult) {
                    alert(jsonResult);
                }
            });

function getStrPayJson() {
        var json = [];
        var arrInput = $("input[name=Coupon]").not(":disabled");
        $.each(arrInput, function (i, item) {
            if (item.value != "") {
                var obj = { "UserId": item.id, "Coupon": item.value };
                json.push(obj);
            }
        });
        return json;
    }