function initExternalLinks() {
  var as = document.getElementsByTagName("a");
  for (var i = 0; i < as.length; i++) {
    if (as[i].getAttribute("rel") == "external") {
      as[i].onclick = openNewWindow;
    }
  }

  function openNewWindow() {
    window.open(this.href);
    return false;
  }
}