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;