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;