function externalLinks() {
	if (!document.links) return;
	var links = document.links;
	var pattern = new RegExp("(^| )external( |$)");
	for (var i = 0; i < links.length; i++) {
		var link = links[i];
		if (link.getAttribute("href") && pattern.test(link.getAttribute("rel"))) link.target = "_blank";
	}
}
addDOMLoadEvent(externalLinks);