function showhide(el) {
  return;
  var active = null;
  if (el.className.indexOf("actief") == -1) {
    el.className += " actief";
    active = el;
  }
  for (i=0; i<el.parentNode.childNodes.length; i++) {
    if (el.parentNode.childNodes[i].tagName == "LI" && el.parentNode.childNodes[i] != active) {
      el.parentNode.childNodes[i].className = el.parentNode.childNodes[i].className.replace("actief", "")
    }
  }
}

function popup(url) {
  window.open(url);
}