请帮助解决定制autentification问题

我有简单的身份验证类型我在数据库中如果userName和密码存在我创建FormsAuthenticationTicket并添加它HttpContext.Current.Response.Cookies.Add（cookie）;当我在请求之前检查HttpContext.Current.User.Identity.IsAuthenticated它返回false但是如果我检查global.asax Application_AuthenticateRequest（对象发送者，EventArgs e）以便跟随请求HttpContext.Current.User.Identity.IsAuthenticated返回true

public static bool Login(string userName, string pass)
    {
        using (SqlConnection conn = new SqlConnection(connectionString))
        {
            try
            {
                conn.Open();
                string comand = string.Format("Select * From ChatUser Where " +
                "userName = '{0}' and pass ='{1}'", userName, pass);
                SqlCommand cmd = new SqlCommand(comand, conn);
                var reader = cmd.ExecuteReader();
                if (!reader.HasRows)
                {
                    conn.Close();
                    return false;
                }
                while (reader.Read())
                {
                    string id = reader["id"].ToString();
                    FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
                    1, id, DateTime.Now, DateTime.Now.AddMinutes(30),
                    false, null, FormsAuthentication.FormsCookiePath);
                    string hashCookies = FormsAuthentication.Encrypt(ticket);
                    HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, hashCookies);
                    HttpContext.Current.Response.Cookies.Add(cookie);

                }
                conn.Close();
                JoinMesage();
                return true;
            }


            catch (Exception ex)
            {
                //write in log file
                return false;
            }
        }
    }

    public static void JoinMesage()
    {
        string userId;
        if (HttpContext.Current.User != null)
        {
            userId = HttpContext.Current.User.Identity.Name;
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                string comand = string.Format("Insert into Messages (userID,mesageDate,userStatus)"
                    + " Value('{0}','{1}','{2}')", userId, DateTime.Now, true);
            }
        }


    }