function externalLinks(){
  if(!document.getElementsByTagName)return false;
  if(!document.getElementsByTagName("a"))return false;
  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.getAttribute("href").match(/^http:\/\//)))
      {
        anchor.target="_blank";
      }
  }
}
function init(){
  externalLinks();
}
window.onload=init;