title: private message using websockets
body: <p>How can we implement a private message system (client to client) using Websockets (and PHP)? </p>
  
  <p>From what I understood, the server broadcasts the message and all of the clients can receive the message through connection.onmessage event handler. I was wondering if there is a way to send the message to only a targeted user in the websockets?</p>