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") == "external")
       anchor.target = "_blank";
 }
}

function changeClass(en,cn) {
if(!document.getElementById) return;
var element = document.getElementById(en);	
	element.className = cn;
}

window.onload = function(){ 
  externalLinks()
  }