请教高手,有个JS的列子单选题判断的列子,想改成多选的判断?

    <script type="text/javascript">
                $("input:radio").click(function(){
                    var _this = $(this);
                    var qid = _this.attr('rel');
                    if(_this.val() == $("#rightanswer_"+qid).html())
                    {
                        _this.parents('.media-body').addClass('alert-success').addClass('alert').html('恭喜您回答正确！');
                    }
                    else
                    {
                        _this.parents('.media-body').addClass('alert-error').addClass('alert').html('回答错误，正确答案为：'+$("#rightanswer_"+qid).html()+'，您选择的答案是：'+_this.val());
                    }
                    $('.questionbtn').addClass('hide');
                    $('.answerbox').removeClass('hide');
                });
            </script>