public bool checkLogin(string login, string password)
        {
            Database.Database_DAO.Database db = new Database.Database_DAO.Database();
            db.Connect();

            SqlCommand command = db.CreateCommand(SQL_SELECT_LOGIN);

            command.Parameters.AddWithValue("@login", login);

            SqlDataReader reader = db.Select(command);

            Collection <Database.Client> Clients = Database.Database_DAO.ClientTable.Read(reader);

            Database.Client Client = null;
            if (Clients.Count == 1)
            {
                Client = Clients[0];
            }
            else
            {
                return(false);
            }
            reader.Close();
            db.Close();

            if (Client.password == password)
            {
                return(true);
            }
            else
            {
                return(false);
            }
        }