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"; 
			if(anchor.getAttribute("title")) anchor.setAttribute("title", anchor.getAttribute("title") + " (opens in a new window)");
			else anchor.setAttribute("title", "Opens in a new window");
		}
	} 
} 

window.onload = externalLinks;