nt(e) });
    var win = aEvent.source;
    if (argv[0] === "REGISTER" && argc === 1) {
      this.remoteWindows.push(win);
      this.postMsg(win, "REGISTERED", document.title, this.slides.length);
      this.postMsg(win, "CURSOR", this.idx + "." + this.step);
      return;
    }
    if (argv[0] === "BACK" && argc === 1)
      this.back();
    if (argv[0] === "FORWARD" && argc === 1)
      this.forward();
    if (argv[0] === "START" && argc === 1)
      this.goStart();
    if (argv[0] === "END" && argc === 