title: Method called from codebehind with ajax return undefine
body: <p>I want to get value from codebehind that then I call it using ajax, but I got nothing, in succes it just show undefine , here the code</p>
  
  <pre><code>function PopMensaje() {
  
              $.ajax({
                  type: "POST",
                  url: "/WebForms/Modulo Tramites/ProcesosTramites/frmIniciarTramite.aspx/metodoajax",
                  data: '{}',
                  contentType: "application/json; charset=utf-8",
                  dataType: "json",
                  success: function (result) {
                      alert("retorno "+result.d);
                  },
                  error: function () {
                      alert('Ocurrio un error');
  
                  }
              });
  </code></pre>
  
  <p>on calling show </p>
  
  <pre><code>    };
  </code></pre>
  
  <p>and this the function in codebehind</p>
  
  <pre><code>  [WebMethod]
    public static string metodoajax(){
          return "123";
      }
  </code></pre>
  
  <p>on calling shows "retorno undefine".I expect it shows  "retorno 123"</p>
  
  <p>What I'm doing wrong? How to fix this? </p>