how to get a result from MVC controller with delegate using ajax

See more:

C#

Ajax

MVC

Delphi

delegates

I'm having a tough time getting the result from my controller, it has a function that contains a delegate funciont passint as a parameter.

so the result is awais empty and then goes back after its finished.

HTLM

<label>Name:</label>
<input id="txtName" type="text" />
<label>lastName:</label>
<input id="txtlastName" type="text" />

<pre lang="HTML"></pre>&lt;button onclick="SayHello()">HELLO</button>

JS

function SayHello() {
        alert("Início");
        var user = CaptureElements();
        var json = JSON.stringify(user);        
        var url = '@Url.Action("SayHello&", "Home")'; 

$.ajax({
    url: url,
    async: false,
    data: json,
    type: 'POST',
    contentType: 'application/json',
    dataType: 'json',
    success: function (data) {
                    $("#aaa")[0].innerHTML = data;                    
                    alert(data);
                }
});    


function CaptureElements() {        
        var name = document.getElementById("txtName").value;
        var lastname = document.getElementById("txtlastName").value;        
        return (name == "" ? null : { name: name, lastname: lastname })

    }

C#

 [HttpPost]
 public ActionResult SayHello(Usuario user)
 {
   var Proxy = content();
   string hello= "";
   Proxy.SayHello(user.name.ToString(), user.lastName.ToString(),
                    (String result) =>
                    {
                       hello= result;

                    }, ExceptionCallback);

  return Json(hello);
}

CSharp / DataSnap
The "Proxy" class below was generated by delphi xe5 data snap project.

/**
       * @param FirstName [in] - Type on server: string
       * @param LastName [in] - Type on server: string
       * @return result - Type on server: string
       */
      public delegate void SayHelloCallback(String Result);

      public void SayHello(String FirstName, String LastName, SayHelloCallback callback = null, ExceptionCallback ExCal = null)
      {
        DSRESTCommand cmd = getConnection().CreateCommand();
        cmd.setRequestType(DSHTTPRequestType.GET);
        cmd.setText("TServerMethods1.SayHello");
        cmd.prepare(get_TServerMethods1_SayHello_Metadata());
        InternalConnectionDelegate SayHelloDel = () =>
        {
          if (callback != null)
          {
            try
            {
              callback.DynamicInvoke(cmd.getParameter(2).getValue().GetAsString());
            }
            catch (Exception ex)
            {
              if (ExCal != null) getConnection().syncContext.Send(new SendOrPostCallback(x => ExCal.DynamicInvoke(ex.InnerException)), null);
              else getConnection().syncContext.Send(new SendOrPostCallback(x => BaseExCal.DynamicInvoke(ex.InnerException)), null);
            }
          }
        };
        cmd.getParameter(0).getValue().SetAsString(FirstName);
        cmd.getParameter(1).getValue().SetAsString(LastName);
        getConnection().execute(cmd, this, SayHelloDel, ExCal);
      }

I would really appreciate any help!
Thanks.