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"; 
    } 
   } 
 } 
 window.onload = externalLinks;