html5新增属性

<style type="text/css">
form{
width: 100%;
min-width: 400px;
max-width: 800px;
margin: 0 auto;
font-size: 13px;
}
input{
display: inline-block;
width: 100%;
height: 40px;
margin: 10px 0px;
}
</style>

<form>
<fieldset>
<legend>新增表单属性</legend>
<label>
用户名:<input type="text" name="uname" autofocus="autofocus"  required="required" placeholder="用户名格式:李四" autocomplete="off"/>

</label>

<input type="submit" value="提交" />
</fieldset>

</form>