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("class") == "document")
 anchor.target = "_blank";
 }
}
 window.onload = externalLinks;