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") == "nofollow")
     		anchor.target = "_blank";
 }
}
window.onload = externalLinks;