unable to retreive data from WCF service from jquery

Question

Hi All,

        Iam using an wcf web service to retrieve value from database ,iam calling it from jquery ajax call,the problem is getPollDetails.ModelMake is null or not an object.

aspx code:

var varType;

         var varUrl;

         var varData;

         var varContentType;

         var varDataType;

         var varProcessData;

         //Generic function to call AXMX/WCF  Service        

         function CallService() {

             $.ajax({

                 type: varType, //GET or POST or PUT or DELETE verb

                 url: varUrl, // Location of the service

                 data: varData, //Data sent to server

                 contentType: varContentType, // content type sent to server

                 dataType: varDataType, //Expected data format from server

                 processdata: varProcessData, //True or False

                 success: function (msg) {//On Successfull service call

                     ServiceSucceeded(msg);

                 },

                 error: alert('not working')// When Service call fails

             });

         }

         

         //Data Available

         function ServiceSucceeded(result) {

            

             $('span[id=lblmakemodels]').text(result.getPollDetails.ModelMake);-->when i keep break point on (result.getPollDetails.ModelMake) value is coming here also.

             alert(result.getPollDetails.ModelMake);

         }

         function PollingDataJSON(selectdata) {

             alert(selectdata);

             varType = "POST";

             varUrl = "../HttpHandler/GetPollingDataService.svc/getPollDetails";

            

             varData =  JSON.stringify({

                 vehicleno: selectdata,

                                });

             varContentType = "application/json; charset=utf-8";

             varDataType = "json";

             varProcessData = true;

             CallService();

         }

wcf code:

 [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]

    [ServiceBehavior(IncludeExceptionDetailInFaults = true)]

    [DataContract]

    public class GetPollingDataService : IGetPollingDataService

    {

      [DataMember]

        public string ModelMake;

}

 public GetPollingDataService getPollDetails(string vehicleno)

        {

if (dr.Read() != null)

                {

                    objdet.ModelMake = dr["YearMake"].ToString();

                    dr.Close();

                    return objdet;

                }

}

when i keep the break point values is retreiving in objdet.ModelMake.