function externalLinks() {
	if (!document.getElementsByTagName)
		return;
	var as = document.getElementsByTagName("a");
	for (var i = 0; i < as.length; i++) {
		var a = as[i];
		if (a.getAttribute("href") && /external/.test(a.getAttribute("rel")))
			a.target = "_blank";
	}
}

window.onload = externalLinks;