Ajax缓存

//  Ajax缓存 请求一次，页面不会在次访问这个方法，会读取缓存数据$(".routeTips").live("mouseenter",function () {    var $this = $(this);    var billcode = $(this).attr("data-sitecode");    var key = "A027" + billcode;    if (isCache) {        if (cacheRouteTips[key]) {            $this.manhua_bubbletips({ position: "t", value: 35, content: cacheRouteTips[key] + "", last: true });        } else {            if (req) {                req.abort();            }            postData();        }    }else {        postData();    }    function postData() {        req = $.ajax({            type: "post",            dataType: "json",            url: "/postdate.aspx",            data: "id=" + billcode + "&type=A018",            cache: false,            timeout: 20000,            success: function (msg) {                if (msg.Result[0]["status"] == "true") {                    $this.manhua_bubbletips({ position: "t", value: 35, content: msg.Result[0]["site"] + msg.Result[0]["tel"] + "", last: true });                    cacheRouteTips[key] = msg.Result[0]["site"] + msg.Result[0]["tel"];                }            }        });    }});