/// <summary>
        /// Returns bank user by user name and password.
        /// </summary>
        /// <param name="userName">User name.</param>
        /// <param name="password">Password.</param>
        /// <returns>Specified user or null if the user is not exists in the DB.</returns>
        public static BankUser GetUser(string userName, string password)
        {
            if (string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(password))
            {
                return null;
            }

            string hashedPassword = GetHashValue(password);

            try
            {

                BankUserDAL userDal = new BankUserDAL();
                return userDal.GetUser(userName, password);

            }
            catch (Exception)
            {

                return null;
            }
        }
        /// <summary>
        /// Check exiting of the user by user name.
        /// </summary>
        /// <param name="userName">User name.</param>
        /// <returns>true if exist.</returns>
        public static bool IsExist(string userName)
        {
            if (string.IsNullOrEmpty(userName))
            {
                return false;
            }

            BankUserDAL bankUserDal = new BankUserDAL();
            return bankUserDal.IsExist(userName);
        }