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;