show busy status in chat app.

Question

Hello Everyone,

 

I need help for my web chat application.  I want to add a feature in my chat application that if a person already busy in chating with 2 guys  or 3rd one want to chat with the same guy who is busy in chating with 2 guys already then show the message(popup)on 3rd users page that  "He/She is busy. Plz try Later..  ".

 How can i achieve it.Please Help me

 

Tools & Tech. which i used in my chat application are bellow:-

 

Asp.net Framework 4.0.

Ajex.

Ado.net

D.B:-Sql Server