index.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>工具函数</title>
<script type="text/javascript" src="jquery-1.10.1.js"></script>
<script type="text/javascript" src="jquery.validate.js"></script>
<script type="text/javascript" src="demo.js"></script>
<link type="text/css" rel="stylesheet" href="style.css" />
</head>
<body>
<form action="123.html">
<p>用 户 名:<input type="text" class="required" minlength='2' name="user" />(*)</p>
<p>电子邮件:<input type="text" class="required email" name="email" />(*)</p>
<p>网 址:<input type="text" class="url" name="url" /></p>
<p><input type="submit" value="提交" /></p>
</form>
</body>
</html>
demo.js
$(function(){
//第一步,引入 jquery 文件
//第二步,引入 validate.js
//第三步,加载 validate
$('form').validate();
//第四步,不得为空,给表单字段 class="required"
});
效果图: