2
4

2 回答 2

4 
<select>
    <option value="">Please select an option</option>

<option> content is only used when the value is not empty.

http://jsfiddle.net/s5AVg/

于 2013-04-25T19:04:02.363 回答
4 
<select>
    <option style="display:none">please select an option</option>
    <option disabled="disabled">I am a line</option>
    <option>1</option>
    <option>2</option>
    <option>3</option>
</select>
于 2013-05-12T12:52:38.177 回答