title: Emit to a specific client with socketId via Socket.IO 1.0
body: <p>I know it's very popular question, but i didn't find answer for my question.
  Very similar question: 
  <a href="https://stackoverflow.com/questions/24135188/socket-io-how-can-i-get-the-socketid-when-i-emit-to-a-specific-client-in-socket">socket.IO: how can i get the socketid when i emit to a specific client in socket.io 1.0</a></p>
  
  <p>I want emit to a specific client with socketId, But i get an error, see below.</p>
  
  <pre><code>socket.join( gameId );
  io.sockets.connected( opponent ).join( gameId );
  socket.emit( 'ready', gameId, 'X', x, y );
  io.sockets.connected( opponent ).emit( 'ready', gameId, 'O', x, y );
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>          io.sockets.connected( opponent ).join( gameId );
                       ^
  TypeError: Property 'connected' of object #&lt;Namespace&gt; is not a function
  </code></pre>
  
  <p>Please help me.
  Forgot to say that, impossible to use <code>.join(gameId)</code> with <code>io.to(socket.id)</code> </p>