function addEvent(obj, evType, fn) {
	if (obj.addEventListener) {
		obj.addEventListener(evType, fn, false);
		return true;
	} else if (obj.attachEvent) {
		var r = obj.attachEvent("on"+evType, fn);
		return r;
	} else {
		return false;
	}
}

function openExternal(link) {
	window.open(link, "_blank");
	return false;
}

function checkForExternalLinks() {
	if ( document.getElementsByTagName ) {
		links=document.getElementsByTagName("a");
		for (i=0; i < links.length; i++) {
			if ( links[i].className == "external" ) {
				links[i].onclick=function() { return openExternal(this); }
			}
		}
	}
}

addEvent(window, 'load', checkForExternalLinks);