I added the refrence and give my bing AppID but i got this error when i run the code and click go (for search):

 

System.ServiceModel.FaultException was unhandled
  Message=Client error
  StackTrace:
       at System.ServiceModel.DiagnosticUtility.ExceptionUtility.BuildMessage(Exception x)
       at System.ServiceModel.DiagnosticUtility.ExceptionUtility.LogException(Exception x)
       at System.ServiceModel.DiagnosticUtility.ExceptionUtility.ThrowHelperWarning(Exception e)
       at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
       at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs, IAsyncResult result)
       at System.ServiceModel.ClientBase`1.ChannelBase`1.EndInvoke(String methodName, Object[] args, IAsyncResult result)
       at BingDemo2.BingWebService.BingPortTypeClient.BingPortTypeClientChannel.EndSearch(IAsyncResult result)
       at BingDemo2.BingWebService.BingPortTypeClient.BingDemo2.BingWebService.BingPortType.EndSearch(IAsyncResult result)
       at BingDemo2.BingWebService.BingPortTypeClient.EndSearch(IAsyncResult result)
       at BingDemo2.BingWebService.BingPortTypeClient.OnEndSearch(IAsyncResult result)
       at System.ServiceModel.ClientBase`1.OnAsyncCallCompleted(IAsyncResult result)
       at System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously)
       at System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously, Exception exception)
       at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.CallComplete(Boolean completedSynchronously, Exception exception)
       at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.FinishSend(IAsyncResult result, Boolean completedSynchronously)
       at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.SendCallback(IAsyncResult result)
       at System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously)
       at System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously, Exception exception)
       at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelAsyncRequest.OnGetResponse(IAsyncResult result)
       at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClassa.<InvokeGetResponseCallback>b__8(Object state2)
       at System.Threading.ThreadPool.WorkItem.doWork(Object o)
       at System.Threading.Timer.ring()