//--------------------------------------------------------------------------------------------------------------------------------------------------
 /// <summary>
 /// Traniee functions
 /// </summary>
 public void Add_traniee(BE.Trainee trainee)
 {
     if ((DateTime.Today - trainee.Birth_date) < new TimeSpan(BE.Configuration.Minimum_Trainee_age * 365, 0, 0, 0))
     {
         throw new Exception("שגיאה בהכנסת תלמיד: התלמיד לא בגיל הנצרך");
     }
     Dal.Add_traniee(trainee);
 }