var onload_comparte = window.onload;
window.onload = function () {
if (onload_comparte) onload_comparte();
setSharedUrls();
}

function setSharedUrls(){
        //enlace_facebook
        setUrl("enlace_facebook","http://www.facebook.com/sharer.php?u="+window.location);
        setUrl("enlace_delicious","http://del.icio.us/post?url="+window.location);
        setUrl("enlace_twitter","http://twitter.com/home?status="+window.location);
        setUrl("enlace_technorati","http://www.technorati.com/faves?add="+window.location);             
        setUrl("ultimo","url_ultimo");               
}

function setUrl(id,url){
  var oLink=document.getElementById(id);
  if(oLink!=null){
    oLink.href=url;        
  }
}