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);
}
}