ajax scriptaculous 框架

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script src="js/prototype.js" type="text/javascript"></script>
<script src="js/scriptaculous.js" type="text/javascript"></script>
</head>
<body>
<input type="text" id="auto1" size="20">
<div id="auto_list"></div>
<script type="text/javascript" language="javascript" charset="utf-8">
new Ajax.Autocompleter("auto1","auto_list","list_u.asp?cx="+escape($F("auto1")),{ method:"post"} );
</script>
</body>
</html>为什么显示不了自动完成？？？