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.href && anchor.rel == "external")) {
			anchor.target = "_blank"; 
		}
	}
}
	
addEvent(window, 'load', externalLinks);