解析jquery中的ajax缓存问题

function ajax_show(apartId,roomClass,sortTile){
          HX_THIS_FANGXING_NUM=sortTile;
          huxing_pic_set_color();   
          var this_li=$('#title_'+sortTile);
          var cache=this_li.data("cache");
          if(undefined!=cache){
           var data_arr =cache.split('-');
            xg_pic_links=data_arr[0];//缓存记录
            layout_pic_links=data_arr[1];
            layout_big_pic_links=data_arr[2];
            product_links=data_arr[3];
               xg_pic_deal_array();
            xg_show_pic(xg_now_pic_id);
            }else{
                   $.ajax({//用JQ的缓存cache在FF下还是会发起新请求
                    type: "POST",
                   url: "index.php?m=content&c=index&a=ajax_all_pic",
                  data: "apartId=123&roomClass=123",
                 dataType:'text',
                  success: function(backdata){
                       this_li.data('cache',backdata);//缓存记录    
                       var data_arr =backdata.split('-');
                       xg_pic_links=data_arr[0];   
                       layout_pic_links=data_arr[1];
                       layout_big_pic_links=data_arr[2];
                       product_links=data_arr[3];
                       xg_pic_deal_array();
                       xg_show_pic(xg_now_pic_id);            
               }
           });

          }
    }