$(function () {
            $("#btnCheck").bind("click", function () {
                $.ajax({
                    url:"http://www.imooc.com/data/check.php",
                    data: { num: $("#txtNumber").val()},
                    dataType:"text",
                    type:"post",
                    success: function (data) {
                        $("ul").append("<li>你输入的<b>  "
                        + $("#txtNumber").val() + " </b>是<b> "
                        + data + " </b></li>");
                    }
                });
            })
        });

这里type不添加,实际上不会传输我们从前台传过去的num值,然后不管输入奇数还是偶数,其实服务器中的num都被初始化为0?所以结果才会一直显示判断为偶数?