public bool CreateTeam(string name, decimal price, string description,
                         DateTime startPeriod, DateTime endPeriod,
                     int maxNumberOfParticipants, string trainingSchedule)
 {
     try
     {
         ITeam team = new Team(name, price, description, startPeriod, endPeriod, maxNumberOfParticipants, trainingSchedule, true);
         team = TeamPersistence.CreateTeam(team);
         if (team != null)
         {
             teamList.Insert(0, team);
             return true;
         }
     }
     catch (Exception)
     {
         return false;
     }
     return false;
 }
        public bool UpdateTeam(string name, decimal price, string description, DateTime startPeriod, DateTime endPeriod, int maxNumberOfParticipants, string trainingSchedule, int activityId, bool activated)
        {
            try
            {

                ITeam thisTeam = new Team(name, price, description, startPeriod, endPeriod, maxNumberOfParticipants, trainingSchedule, activated, activityId);
                if (TeamPersistence.UpdateTeam(thisTeam))
                {
                    ITeam teamInList = RetrieveSingleTeam(thisTeam.ActivityId);
                    updateTeamProperties(teamInList, thisTeam);
                    return true;
                }
                return false;
            }
            catch (Exception)
            {
                return false;
            }
        }
        public static List<ITeam> RetrieveTeams()
        {
            List<ITeam> teamList = new List<ITeam>();

            if (Connect())
            {
                SqlCommand Command = Connection.CreateCommand();
                Command.CommandType = CommandType.StoredProcedure;
                Command.CommandText = "fif_team_retrieve";

                SqlDataReader	dataReader = Command.ExecuteReader();

                while (dataReader.Read())
                {
                    int id = int.Parse(dataReader["activity_id"].ToString());
                    string name = dataReader["name"].ToString();
                    decimal price = decimal.Parse(dataReader["price"].ToString());
                    string desciption = dataReader["description"].ToString();
                    DateTime startPeriod = DateTime.Parse(dataReader["start_period"].ToString());
                    DateTime endPeriod = DateTime.Parse(dataReader["end_period"].ToString());
                    int maxNumberOfParticipants = int.Parse(dataReader["max_number_of_participants"].ToString());
                    string trainingSchedule = dataReader["schedule"].ToString();

                    ITeam team = new Team(id, name, price, desciption, startPeriod, endPeriod, maxNumberOfParticipants, trainingSchedule);
                    teamList.Add(team);
                }
                Disconnect();
                return teamList;
            }
            return null;
        }