ช่วยดู code การรับส่งค่าแบบ json ที่ใช้กับ webservice(asp.net c#) ด้วยค่ะ ขอบคุณมากค่ะ

$(document).ready(function () {
              $('a').click(function () {
                  $.ajax({
                      type: "POST",
                      url: "WebService.asmx/LoadDisease",
                      data: "{'code':'A1'}",
                      contentType: "application/json; charset=utf-8",
                      dataType: "json",
                      success: function (data) {
                          alert(data.disease_name)
                      },
                      error: function (data) {
                          alert(data.responseText)
                      }
                  });
                  //$('#dialog').dialog()
              });
          });

[WebMethod]
        [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
        public string LoadDisease(string code)
        {
            using (DataClassesPigDataContext dbc = new DataClassesPigDataContext())
            {
                var objdisease = (from data in dbc.trn_diseases where data.disease_code == code select data).FirstOrDefault();

                JavaScriptSerializer js = new JavaScriptSerializer();
                string reJSON = js.Serialize(objdisease);
                return reJSON;
            }
        }