Post object to a WCF method - wcf

Question

I am a newbie to both RestSharp and WCF and I am trying to write a working sample that has a post method which takes a string and an object as parameters. I have looked at another post here where someone asked the same question and I still couldn't get it to work. Can someone please point me in the right direction. I debugged the code and I am getting a null in the object. It seems like its pretty straight forward but I am not sure what I am missing. This is what I have so far.
Server side:
[OperationContract]
[Description("addUser")]
[WebInvoke(Method = "POST", UriTemplate = "/addUser?id={id}", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.WrappedRequest)]
TSCRUResponse addUser(string id, User usr);
public TSCRUResponse addUser(string id, User usr)
{
TSCRUResponse r = new TSCRUResponse();
r.status = id + usr.name + usr.age + usr.gender;
return r;
}
The first parameter for the above method comes through OK but not the object.
These are the objects:
[DataContract]
public class TSCRUResponse
{
[DataMember(Name = "status")]
public string status { get; set; }
}
[DataContract]
public class User
{
[DataMember(Name = "name")]
public string name { get; set; }
[DataMember(Name = "age")]
public string age { get; set; }
[DataMember(Name = "gender")]
public string gender { get; set; }
}
Client side :
public void postmethod(string uri)
{
ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateRemoteCertificate);
RestClient client = new RestClient();
client.BaseUrl = "http://localhost:1119/TestService.svc/";
client.Authenticator = new HttpBasicAuthenticator("username", "password");
RestRequest request = new RestRequest("addUser?id={id}", Method.POST);
request.AddHeader("Accept", "application/json");
request.JsonSerializer = new RestSharp.Serializers.JsonSerializer();
request.RequestFormat = DataFormat.Json;
request.AddParameter("id", "12839", ParameterType.UrlSegment);
User itm = new User { age = "40", name = "user1", gender = "M" };
request.AddBody(itm);
var response = client.Execute<TSCRUResponse>(request);
TSCRUResponse addres = response.Data;
Console.WriteLine(addres.status);
}