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";
    }
}
addOnloadEvent(externalLinks);