Chat bot reply with face book username

Question

I have created a chatbot using Visual studio (c#) and Microsoft azure account. It replies well without error.

Now I want to my chatbot reply to display with the facebook username as the first default message.

It is also Ok .

 

 But it is Repeatedly comming(FbUsername) for any question. It means I am sending Hi to   my bot it will respond  "Hi Durgaprasad"  . again i am sending what is chat bot then my bot  is Hi Durgaprasad and answer that question. 

 

public async Task<HttpResponseMessage> Post([FromBody]Activity activity)

{

if (activity.Type == ActivityTypes.Message)

{

string userName = "";

if (activity.From.Name != null)

userName = activity.From.Name;

ConnectorClient connector = new ConnectorClient(new Uri(activity.ServiceUrl));

Activity reply = activity.CreateReply("hello" + userName);

activity.TextFormat = "GreetingIntent";

await connector.Conversations.ReplyToActivityAsync(reply);

await Conversation.SendAsync(activity, () => new Dialogs.RootDialog());

}

else

{

HandleSystemMessage(activity);

}

var response = Request.CreateResponse(HttpStatusCode.OK);

return response;

}

 

 But i want to users sending Hi or Hello then only it will come 

 How to do this