function InitExternalLinks() {
 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")  &&
      anchor.getAttribute("rel").indexOf("external") >= 0)
  {
   if (anchor.getAttribute("_target"))
        anchor.target = anchor.getAttribute("_target");
   else anchor.target = "_blank";
  }
 }
}

if (window.addEventListener)
 window.addEventListener('load',InitExternalLinks,false); else
if (window.attachEvent)
 window.attachEvent('onload',InitExternalLinks);