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";
			if (anchor.getAttribute("title")){
				anchor.title = anchor.getAttribute("title") + " (se abre en nueva ventana)";
			}
			else{
				anchor.title = "(se abre en nueva ventana)";
			}
		}
	}
	
}
window.onload = externalLinks;