How to send json object to C# web server

Question

I write this java script to send json object to c# web service. but its not work..Why is it? this is my javascript..

<script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery- 1.5.1.js"></script>
<script type="text/javascript">
 function BindJson() {
 document.getElementById("demo").innerHTML=Date();
 $.ajax({
 type: "POST",
 url: "Service1.asmx/SerializeJson",
 data: JSON.stringify({ person:{ firstName: "Denny" }}),
 contentType: "application/json; charset=utf-8",
 dataType: "json",
 success: function (data2) {
 alert(data2.d);
 },
 error: function (request, status, errorThrown) {
 alert(status);
 }
 }); 
 } 
</script>

And this is my server class ..

 [System.Web.Script.Services.ScriptService]
 public class Service1 : System.Web.Services.WebService
 {
 [WebMethod]
 public string SerializeJson(Person person)
 {
 return "Success";
 }
 public class Person
 {
 public string firstName { get; set; } 
 } 
 }

Answer 1

You should not use JSON.stringify because when you specify content type of JSON, jQuery will convert it using JSON.stringify.

 data: JSON.stringify({ person:{ firstName: "Denny" }}),
 contentType: "application/json; charset=utf-8",
 dataType: "json",

Change it to

 data: { person:{ firstName: "Denny" }},
 contentType: "application/json; charset=utf-8",
 dataType: "json",

Also you don't need to send person as a member of object unless it is required.

 data: { firstName: "Denny"},
 contentType: "application/json; charset=utf-8",
 dataType: "json",

Answer 2

data option for .ajax expects a name value pair string, or an object

data: { "myjson": JSON.stringify({ person:{ firstName: "Denny" }}) },
//OR
data: "myjson="+JSON.stringify({ person:{ firstName: "Denny" }}),
//Or just send the data values and retrieve in the way you get GET or POST variables in C#
data: { person:{ firstName: "Denny" }},