function externalLinks(){
	var links = document.getElementsByTagName('a');
	
	for(var i=0; i<links.length; i++){
		if(links[i].rel == 'external'){
			links[i].target = '_blank';
		}
	}
}

if (window.addEventListener)
	window.addEventListener("load", externalLinks, false)
else
	window.onload=externalLinks()