PHP：如何使用表单类型在PHP中选择菜单？

My input type text is working fine.

  <textarea rows='3' cols='30' name='comments' onclick='make_blank();'>
    <?php if(isset($_POST['comments'])) echo $_POST['comments']; ?>
  </textarea>

However, once I try to create a select list menu (BELOW) it does not work.

<select>
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
 <?php if(isset($_POST['package'])) echo $_POST['package'];?>
</select> 

Help would be appreciated. Many Thanks!

Your select doesn't have the name attribute:

<select name="package">
    <option value="volvo">Volvo</option>
    <option value="saab">Saab</option>
    <option value="mercedes">Mercedes</option>
    <option value="audi">Audi</option>
    ...

use following

 if(isset($_POST['package'])) echo "<option>" . $_POST['package'] . "</option>";