Event.observe(window, 'load', function(e) {
  var links = document.getElementsByTagName('a');
  for(i=0; i<links.length; i++) {
  var d = links[i].href.split('/');
  if(d.length > 2) {
     if(d[2] != window.location.href.split('/')[2]) {
        links[i].setAttribute('target', '_blank');
     }
  }
}
});