private void AddParticipation(object obj)
        {
            sel_part = new ParticipationModel();
            ParticipationWindow cw = new ParticipationWindow(sel_part);

            if (cw.ShowDialog() == true)
            {
                sel_part.Project_ID = Pr.ID;
                db.AddParticipation(sel_part);
                db.Save();
                d1.Participations = db.GetAllParticipations(Pr.ID);
            }
        }
        private void EditParticipation(object obj)
        {
            if (sel_part != null)
            {
                ParticipationWindow cw = new ParticipationWindow(sel_part);

                if (cw.ShowDialog() == true)
                {
                    db.UpdateParticipation(sel_part);
                    db.Save();
                    d1.Participations = db.GetAllParticipations(Pr.ID);
                }
            }
            else
            {
                MessageBox.Show("Вы ничего не выбрали!");
            }
        }