window.onload = externalLinks;

function externalLinks() {
  	 if(!document.getElementsByTagName) return;
  	 var links,a,i;
  	 links = document.getElementsByTagName("a");
  	 for(i=0;i<links.length;i++) {
  	   	 a = links[i];
  	   	 if(a.getAttribute("rel") && 
a.getAttribute("rel").indexOf("external") > -1) {
  	   	   	 a.onclick = function() {
  	   	   	   	 window.open(this.href);
  	   	   	   	 return false;
  	   	   	 }
  	   	 }
  	 }
}