Set all links target to _blank on a XHTML 1.0 Strict using jquery

As explained here, opening links in a new window is no longer possible via target=_blank in XHTML 1.0 strict. This code is a workaround using Javascript:

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;

A link with attribute rel set to external will open in a new window:

<a rel="external" href="http://castfortwo.blogpspot.com/">cast42</a>

On the Friendfeed realtime embed code, I saw they use jquery to do the job:

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.js">
<script type="text/javascript"> 
$("body").mousedown(function(e) {
for (var target = e.target; target; target = target.parentNode) {
  if (target.tagName == "A") {
    if ((document.location.href.split("#")[0] + "#") == target.href) {
      return;
    }
    target.target = "_blank";
    return;
    }
}
});
</script> 

The advantage is that all links will open in a new window, except if the refere to an anchor in the page. Hence there's no need to add the attribute rel to each anchor.