// nicked from http://www.sitepoint.com/article/1041/1
// by Kevin Yank 
// Do external links like this: 
// <a href="document.html" rel="external">external link</a>

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";
 }
}
window.onload = externalLinks;