js 对Cookie进行增删改操作

   //增加
        function setCookie(name, value) {
            var Days = 30;
            var exp = new Date();
            exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
            document.cookie = name + "=" + escape(value) + ";expires=" + exp.toGMTString();
        }
        //获取
        function getCookie(name) {
            var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");

            if (arr = document.cookie.match(reg))
                return unescape(arr[2]);
            else
                return null;
        }
        //删除
        function delCookie(name) {
            var exp = new Date();
            exp.setTime(exp.getTime() - 1);
            var cval = getCookie(name);
            if (cval != null)
                document.cookie = name + "=" + cval + ";expires=" + exp.toGMTString();
        }