jquery用于bootstrap选择验证

Question

Bootstrap 3验证在选择中无法正常工作。 html code is

<div class="control-group">
    <label class="control-label">Select std.<span class="f_req">*</span></label>
    <div class="controls">
       <select name="std" class="span5">
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
          <option value="4">4</option>
          <option value="5">5</option>
       </select>
    </div>
</div>

javascript是 rules: { std: { required : true } }
请帮帮我..提前谢谢