jquery怎么删除css样式

<script type="text/javascript">

       $(function(){

           $("li").mouseover(function(){

               //添加css样式

               $(this).css("background","#ffdd00");

           });

           $("li").mouseout(function(){

               //移出css样式

               $(this).css("background","");

           });

       });

   </script>