var i = 0;
var attRel = null;
var linki = document.getElementsByTagName("a");

for (i = 0; i < linki.length; i++) {
	attRel = linki[i].getAttribute("rel")||0;
	if (attRel != 0 && attRel.indexOf("external") >= 0) {
		linki[i].target = "_blank";
	}
}