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).load(function() {
    // external links
    externalLinks();
});