input中添加图标的问题（已解决）

<div class="form-group has-feedback">
      <div class="col-sm-4">
          <input type="text" class="form-control" id="inputName" placeholder="提交人"/>
          <span class="glyphicon glyphicon-user form-control-feedback " aria-hidden="true"></span>
     </div>
</div>