function external_links()
{
	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 = external_links;