function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function () {
			oldonload();
			func();
		}
	}
}

var externalLinks = function () {
	var links = document.getElementsByTagName("a");
	for (i=0; i<links.length; i++) {
		var enlace = links[i];
		if (enlace.getAttribute("target") == "_blank") {
			enlace.className = "external";
		}
	}
	// ahora quita la clase al de powered by
	var pwr = document.getElementById("powered");
	var links = pwr.getElementsByTagName("a");
	links[0].className = '';
}