function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "externo"){
     anchor.target = "_blank";
     anchor.innerHTML = anchor.innerHTML + "<span style='display:none'>site externo, abre nova janela</span>";
     anchor.style.background = "url(images/externo.gif) no-repeat right";
     anchor.style.padding ="0px 14px 0px 0px";
   } else  if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "pdf"){
     anchor.target = "_blank";
     anchor.innerHTML = anchor.innerHTML + "<span style='display:none'>Arquivo PDF, abre nova janela</span>";
     anchor.style.background = "url(images/pdf.gif) no-repeat left";
     anchor.style.padding ="0px 0px 0px 20px";
   }
   }
 }

window.onload = externalLinks;