function externalLinks() {
  if (!document.getElementsByTagName)
            return;
         var anchors = document.getElementsByTagName("a");
         for (var i=0; i<anchors.length; i++) {
             var anchor = anchors[i];
             if (anchor.getAttribute("href") &&
                 anchor.getAttribute("rel") == "external") {
                 anchor.target = "_blank";
             }
             if (anchor.getAttribute("href") &&
                 anchor.getAttribute("rel") == "parent") {
                 anchor.target = "_parent";
             }
         }
}
window.onload = externalLinks;