关于javascript:对js添加cookie的函数封装

addCookie("age","21");    //后三个参数为可选项    function addCookie(key,value,day,path,domin) {        //1.解决保留的门路            //找到html文件前的 / 索引        var index = window.location.pathname.lastIndexOf("/");        var currentIndex = window.location.pathname.slice(0,index);        path = path || currentIndex;        //2.解决默认保留的domin(域名)        domin = domin || document.domin;        //3.解决输出的工夫        if (!day){            document.cookie = key + "=" + value + ";path=" + path + ";domin=" + domin;        }else {            var date = new Date();            date.setDate(date.getDate() + day);            document.cookie = key + "=" + value + ";expires=" + date.toGMTString() + ";path=" + path + ";domin=" + domin;        }    }