public HttpResponseMessage GetComboboxData(string sessionKey, string cond = "", string order = "")
 {
     try
     {
         string columns = "";
         cond = SelReceiveproductDFR.GetComboboxData(sessionKey, out columns, cond, out order);
         return(Request.CreateResponse <string>(HttpStatusCode.OK, JsonConvert.SerializeObject(dta.GetComboboxData(columns, cond, order))));
     }
     catch (Exception e)
     {
         ExceptionHandler.Log(e);
         return(null);
     }
 }