asp.net ajax get 调用(和post不一样，直接返回json才行，否则报错；post不能返回json)

 <script type="text/javascript" >

        $(document).ready(function () {

            $('#Label1').click(function () {

                $.ajax({
                    type: 'GET',
                    url: 'djb.aspx?sfzh=' + '3720510',
                    dataType: 'json',
                    success: function (data) {
                         //不需要解析，直接调用
                        //var parsedJson = $.parseJSON(data);
                        alert(data.msg);
                    },
                    error: function (jqXHR) {
                        alert("失败!");
                    }
                });

                return false;

            });

        });

    </script>

            this.Response.Write( "{\"msg\":\"ok\"}"  );
            this.Response.Flush();
            this.Response.End();