public void SaveExecute()
 {
     if (String.IsNullOrEmpty(Manager.NameAndSurname) || String.IsNullOrEmpty(Manager.DateOfBirth.ToString()) || String.IsNullOrEmpty(Manager.Email) || String.IsNullOrEmpty(Manager.Username) ||
         String.IsNullOrEmpty(Manager.Password) || String.IsNullOrEmpty(Manager.HotelFloor.ToString()) || String.IsNullOrEmpty(Manager.ExperienceWorkingInHotels.ToString()) || String.IsNullOrEmpty(Manager.ProfessionalQualifications) ||
         Manager.DateOfBirth == DateTime.MinValue)
     {
         MessageBox.Show("Please fill all fields.", "Notification");
     }
     else
     {
         try
         {
             MessageBoxResult result = MessageBox.Show("Are you sure you want to save the manager?", "Confirmation", MessageBoxButton.YesNo, MessageBoxImage.Question);
             if (result == MessageBoxResult.Yes)
             {
                 bool isCreated = managers.AddManager(Manager);
                 if (isCreated)
                 {
                     MessageBox.Show("Manager is created.", "Notification", MessageBoxButton.OK);
                     managerView.Close();
                 }
                 else
                 {
                     MessageBox.Show("Manager cannot be created.", "Notification", MessageBoxButton.OK);
                 }
             }
         }
         catch (Exception ex)
         {
             MessageBox.Show(ex.ToString());
         }
     }
 }
 public void SaveExecute()
 {
     try
     {
         managers.AddManager(manager);
         IsVisibleAdding = Visibility.Hidden;
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }
 public void SaveManagerExecute()
 {
     try
     {
         MessageBoxResult result = MessageBox.Show("Are you sure you want to save the manager?", "Confirmation", MessageBoxButton.YesNo, MessageBoxImage.Question);
         if (result == MessageBoxResult.Yes)
         {
             bool isCreated = managers.AddManager(manager);
             if (isCreated == true)
             {
                 MessageBox.Show("Manager is created.", "Notification", MessageBoxButton.OK);
                 IsVisibleAddingManager = Visibility.Hidden;
             }
             else
             {
                 MessageBox.Show("Manager cannot be created.", "Notification", MessageBoxButton.OK);
             }
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }