function externalLinks() {
	if (!document.getElementsByTagName) return;
	var anchors = document.getElementsByTagName("a");
	var areas = document.getElementsByTagName("area");

for (var i=0; i<anchors.length; i++) {
		var anchor = anchors[i];
		var area = areas[i];

		if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "external")
			anchor.target = "_blank";

	}

}
window.onload = externalLinks;