/// <summary>
        /// 设置票据
        /// </summary>
        /// <param name="userName">登录名</param>
        /// <param name="rules">组</param>
        /// <param name="expires">是否持续</param>
        public static void SetTicket(UserEntity user, string rules, bool expires)
        {
            string ticketName = user.ToArray();
            SetTickets(ticketName, rules, expires);
        }
        public static void SetTickets(string ticketName, string rules, bool expires)
        {
            //暂时为永不过期
            //expires = false;
            HttpContext context = HttpContext.Current;
            string userDate = rules;
            DateTime expiration = DateTime.Now.AddMinutes(20);
            FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
            1,  // 版本号
            ticketName,  // 票据名
            DateTime.Now,  // 票据发出时间
            DateTime.Now.AddYears(100),  // 过期时间
            true,  // 是否持久
             userDate// 存储在 Cookie 中的用户定义数据,这里用来存取用户组
            );
            // Encrypt the ticket
            string cookieStr = FormsAuthentication.Encrypt(ticket);
            HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, cookieStr);

            if (!string.IsNullOrEmpty(FormsAuthentication.CookieDomain))
            {
                cookie.Domain = FormsAuthentication.CookieDomain;
                cookie.Path = "/";
            }
            else
            {
                //如果过期
                if (expires)
                {
                    cookie.Expires = expiration;
                }
            }
            context.Response.Cookies.Add(cookie);
        }

 //退出
        protected void LbOutLogin_Click(object sender, EventArgs e)
        {
            tblLoginAfter.Visible = false;
            tblLoginBefure.Visible = true;
            HttpContext context = HttpContext.Current;
            FormsAuthentication.SignOut();
            HttpCookie c = context.Request.Cookies[FormsAuthentication.FormsCookieName];
            if (c == null)
            {
                return;
            }
            c.Expires = DateTime.Now.AddMinutes(-20);
            context.Response.SetCookie(c);


        }