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";
			}
        }
}