1. 引入CSS

<link type="text/css" href="css/style.css" rel="stylesheet" />

2. 引入JS

<script src="js/jquery.js"></script>
<script src="js/index.js"></script>

3. HTML代码

<div class="form-wrap">
	<form action="" method="post">
		<div class="input-wrap">
			<input type="text" id="username">
			<label for="username">用户名</label>
		</div>
		<div class="input-wrap">
			<input type="password" id="password">
			<label for="password">登录密码</label>
		</div>
		<div class="input-wrap">
			<input type="text" id="email">
			<label for="email">个人邮箱</label>
		</div>
		<div class="input-wrap">
			<button>提交</button>
		</div>
	</form>
</div>
<script> 
	$(document).ready(function(){
		$('.form-wrap').finput();
	})
</script>