function externalLinks() {
	if (!document.getElementsByTagName) return;

	var anchors = document.getElementsByTagName("a");
	var mapAreas = document.getElementsByTagName("area");
	
	for (var i=0; i<anchors.length; i++) {

		var anchor = anchors[i];
		
		if (anchor.getAttribute("href") &&
				anchor.getAttribute("rel") == "external")
			anchor.target = "_blank";
	}
	
	for (var i=0; i<mapAreas.length; i++) {	
	
		var area = mapAreas[i];
	
		if (area.getAttribute("href") &&
				area.getAttribute("rel") == "external")
			area.target = "_blank";
	}
}
window.onload = externalLinks;