title: socket.io send packet to sender only
body: <p>I have yet to figure out how to directly respond to only the sender using socket.io</p>
  
  <p>I have learned that io.sockets.emit sends to all clients but I wont to send information back to the sender.</p>
  
  <p>code:</p>
  
  <pre><code>socket.on('login', function (data) {
      db.users.find({username: cc.lowerCase(data.username)}, function(err, users) {
        if (users.length &gt; 0) {
          users.forEach( function(user) {
            console.log(user.length);
            if (user.password == data.password) {
              io.sockets.emit('login', { username: user.username });
            } else {
              io.sockets.emit('error', { message: "Wrong username or password!" });
            }
          });
        } else {
          io.sockets.emit('error', { message: "Wrong username or password!" });
        }
      });
  });
  </code></pre>