code: function _window_onMessage(event){
          var origin = _getOrigin(event);
          if (origin == targetOrigin && event.data.substring(0, config.channel.length + 1) == config.channel + " ") {
              pub.up.incoming(event.data.substring(config.channel.length + 1), origin);
          }
      }
docs: This is the main implementation for the onMessage event.<br/>
  It checks the validity of the origin and passes the message on if appropriate.
  @private
  @param {Object} event The messageevent