public void ListenToServer()
        {
            HCSMSLog.OnWarningLog(this, new NotifyEventArgs("Frontdesk request subscribe service"));
            callBack = OperationContext.Current.GetCallbackChannel <IFrontDeskCallBack>();

            OperationContext.Current.Channel.Faulted += new EventHandler(Channel_Faulted);
            OperationContext.Current.Channel.Closing += new EventHandler(Channel_Closing);

            FrontDeskRequestControl.RegisterService(this, OperationContext.Current.SessionId);
        }
        public void ListenToServer()
        {
            HCSMSLog.OnWarningLog(this, new NotifyEventArgs("Frontdesk request subscribe service"));
            callBack = OperationContext.Current.GetCallbackChannel<IFrontDeskCallBack>();

            OperationContext.Current.Channel.Faulted += new EventHandler(Channel_Faulted);
            OperationContext.Current.Channel.Closing += new EventHandler(Channel_Closing);

            FrontDeskRequestControl.RegisterService(this, OperationContext.Current.SessionId);
        }