server/www/session.js

function Session(modules) {
  var key = null;
  var name = null;

  modules.messaging.addEventListener(["Welcome"], function(o) {
    key = o.key;
  });

  modules.messaging.addEventListener(["Relay", "LogIn"], function(o) {
    if(is(o.from)) {
      name = o.message.name;
    }
  });

  return {
    is: is,
    getKey: getKey,
    loggedIn: loggedIn
  };

  function is(sessionKey) {
    return key == sessionKey;
  }

  function getKey() {
    return key;
  }

  function loggedIn() {
    return name != undefined;
  }
}