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 addLoadEvent(func)
{	var oldonload = window.onload;
	if (typeof window.onload != 'function')
	    window.onload = func;
	else{
	    window.onload = function(){
	        if (oldonload)
	            oldonload();
	        func();
	    }
	}
}

addLoadEvent(function(){externalLinks()});