// 将下面的路径替换位你js文件所在路径。
$js_path = "http://www.soojs.com/js/";

function js_include($script){
var script = document.createElement('script');
script.src = $js_path + $script;
script.type = 'text/javascript';
var head = document.getElementsByTagName('head').item(0);
head.appendChild(script);
}

//题换成你的文件
js_include("prototype.js");
js_include("scriptaculous.js");