<!DOCTYPE html>
<html>
<head>
<title>AJAX实例</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=GB2312">
<script type="text/javascript" src="https://www.jb51.net/js/AjaxJqueryXml.js"></script>
<script type="text/javascript" src="https://www.jb51.net/js/jquery.js"></script>
<!--<link type="text/css" href="https://www.jb51.net/article/styles.css">-->
</head>
<body>
<font color="blue" size="2">请输入用户名：</font>
<input type="text" /><font color="red" size="2"><span >*</span></font><br/><br/>
<input type="submit" value="提交" />
</body>
</html>
这里请自己添加jquery库文件。