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";
		}
}
window.onload = externalLinks;