/**
 * @author votong
 */
function addCss(href) {
	var links = document.getElementsByTagName("link");
	for (var i=0, l=links.length; i<l; i++) {
		if (links[i].href == href) {
			return false;
		}
	}
	var l = document.createElement("link");
	l.setAttribute("type", "text/css");
	l.setAttribute("rel", "stylesheet");
	l.setAttribute("media", "screen");
	l.setAttribute("href", href);
	document.getElementsByTagName("head")[0].appendChild(l);
}
function addJs(src){
	var scripts = document.getElementsByTagName("script");
	for (var i=0, l=links.length; i<l; i++) {
		if (scripts[i].src == src) {
			return false;
		}
	}
	var s = document.createElement("script");
	s.setAttribute("type", "text/javascript");
	s.setAttribute("src", href);
	document.getElementsByTagName("head")[0].appendChild(s);
}