cookie

        //cname 名字
        //cvalue 值
        //exdays 时间            0.01大概25分钟
        function setCookie(cname, cvalue, exdays) {
            var d = new Date();
            d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000));
            var expires = "expires=" + d.toUTCString();
            document.cookie = cname + "=" + cvalue + "; " + expires +"; path=/";
            console.log(d)
        }
        //获取cookie
        function getCookie(cname) {
            var name = cname + "=";
            var ca = document.cookie.split(';');
            for(var i = 0; i < ca.length; i++) {
                var c = ca[i];
                while(c.charAt(0) == ' ') c = c.substring(1);
                if(c.indexOf(name) != -1) return c.substring(name.length, c.length);
            }
            return "";
        }
        //删除 cookie
        function clearCookie(name) {
            setCookie(name, "", -1);
        }