function enhanceLinks(){
  var links = document.getElementsByTagName("a");
  var thisDomain = document.domain.split('www.');
  var thisDomain = (thisDomain[1]) ? thisDomain[1] : document.domain;
  for (var i = 0; i < links.length; i++){
    if(links[i].href.indexOf(thisDomain) == -1 && links[i].href != ''){
      links[i].target='_blank';
    }
  }
}
function addLoadEvent(func){
  var oldonload = window.onload;
  if (typeof window.onload != 'function'){
    window.onload = func;
  }else{
    window.onload = function() {
      if(oldonload){
        oldonload();
      }
      func();
    }
  }
}
addLoadEvent(function(){enhanceLinks();});