var getQueryString = function (name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
    var r = location.search.substr(1).match(reg);
    if (r != null) return unescape(r[2]);
    return '';
}
var getCookie = function (name) {
    var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
    if (arr != null) return unescape(arr[2]);
    return false;
}
var setCookie = function (name, value) {
    var Days = 3000;
    var exp = new Date();
    exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
    document.cookie = name + "=" + escape(value) + ";expires=" + exp.toGMTString();
}

var S4 = function () {
    return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
}
var guid = function () {
    return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
}

var getUid = function () {
    var uidInStorage = localStorage.getItem("uid");
    var uidInCookie = getCookie("uid");
    var uid = uidInStorage || uidInCookie || guid();
    localStorage.setItem("uid", uid);
    setCookie("uid", uid);
    return uid;
}