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;