ThinkPHP实现批量删除

<p class="panel panel-default">
  <p class="panel-heading">
    留言列表
    <a class="btn btn-xs btn-default pull-right" href="javascript:window.history.back();">返回</a>
    <a class="btn btn-xs btn-info pull-right mr-5" id="discard" href="javascript:;">删除</a>
  </p>
  <table class="table">
    <thead>
      <tr>
        <th><input class="all" type="checkbox"/></th>
        <th>id</th>
        <th>名称</th>
        <th>邮箱</th>
        <th>内容</th>
        <th>日期时间</th>
        <th>操作</th>
      </tr>
    </thead>
    <tbody>
       <form>
         <volist name="list" id="vo" empty="$empty">
           <tr>
             <td><input name="delete[]" type="checkbox" value="{$vo.id}" /></td>
             <td>{$vo.id}</td>
             <td>{$vo.name}</td>
             <td>{$vo.email}</td>
             <td>{$vo.subject}</td>
             <td>{$vo.datetime|date="Y-m-d H:i", ###}</td>
           <td>
            <a class="delete" href="javascript:;" data-id="{$vo.id}">删除</a>
           </td>
           </tr>
         </volist>
       </form>
    </tbody>
  </table>
</p>

/* 批量删除 */
  // 全选
  $('.all').click(function() {
    if($(this).is(':checked')) {
      $(':checkbox').attr('checked', 'checked');
    } else {
      $(':checkbox').removeAttr('checked');
    }
  });

  // 删除操作
  $('#discard').click(function() {
    if($(':checked').size() > 0) {
      layer.confirm('确定要删除吗？', {
        btn: ['确定','取消'], //按钮
        shade: false //不显示遮罩
      }, function(){
        $.post("{:U('Single/discard')}", {data: $('form').serializeArray()}, function(res) {
          if(res.state == 1) {
            layer.msg(res.message, {icon: 1, time: 1000});
          } else {
            layer.msg(res.message, {icon: 2, time: 1000});
          }
          setTimeout(function() {
            location.reload();
          }, 1000);
        });
      }, function(){
        layer.msg('取消了删除！', {time: 1000});
      });
    } else {
      layer.alert('没有选择！');
    }
  });

public function discard() {
  $contact = M('contact');
  $deleteArr = I('post.data');
  for($i=0;$i<count($deleteArr);$i++) {
    $contact->delete($deleteArr[$i]['value']);
  }
  $this->ajaxReturn(array('message'=>'删除成功！'));
}