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;