滚动区域不能设置overflow

　　　　var doc = $(document),            win = $(window),                        h = $("#head"),            b = $("#body"),            f = $("#foot"),            itemList = $("#itemList"),            loadDom = $("#loadDom"),            loading = false;         win.scroll(function(){                         var flag = (doc.height()) <= (window.innerHeight + win.scrollTop())               if(!loading && flag) {                loading =true;                loadDom.removeClass("hidden");                setTimeout(function(){                     itemList.append(loadTpl("#tpl-item"));                    loading =false;                },3000);            }        });