function externalLinks() {

 if (!document.getElementsByTagName) return;

 var anchors = document.getElementsByTagName("a");

 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   var testval = anchor.getAttribute("rel");

   if (anchor.getAttribute("href") && (anchor.getAttribute("rel")== "external") )
   {
 //	alert("rel found");
        anchor.target = "_blank";
   }
 }
}
window.onload = externalLinks;