title: node js real time chat read or not read status
body: <p>Actually I have to implement read and not read status in simple node chat with <code>socket.io</code>.</p>
  
  <p>I have already build real time chat application with help of node and <code>socket.io</code>.
  But now what I want is when <strong>user1</strong> send message to another <strong>user2</strong>. <strong>user1</strong> has status of if <strong>user2</strong> read or not read message which is send to another user like whatsup do right now.</p>
  
  <p>any idea about this status.</p>