static void Flow_StateChanged(object sender, Microsoft.Rtc.Collaboration.MediaFlowStateChangedEventArgs e)
 {
     if (e.State == Microsoft.Rtc.Collaboration.MediaFlowState.Active)
     {
         var flow = sender as AudioVideoFlow;
         var ivr  = new IVRMenu();
         ivr.StartWithWelcome(flow, _server);
     }
 }
 static void Flow_StateChanged(object sender, Microsoft.Rtc.Collaboration.MediaFlowStateChangedEventArgs e)
 {
     if (e.State == Microsoft.Rtc.Collaboration.MediaFlowState.Active)
     {
        
         var flow = sender as AudioVideoFlow;
         var ivr = new IVRMenu();
         ivr.StartWithWelcome(flow, _server);
     }
 }