form表单 datalist 和legend
<form action="" method="post" >
<fieldset>
<legend>
表单元素
</legend>
<input type="text" placeholder="请输入">
<input type="text" list="mylist" placeholder="输入或选择">
<datalist id="mylist">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</datalist>
</fieldset>
</form>