window.onload = function () {
  // nahradenie _blank v hypertextoch
  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";
  }
};