partial void Deleteuser(user instance);
 partial void Updateuser(user instance);
		private void detach_users(user entity)
		{
			this.SendPropertyChanging();
			entity.usergroup = null;
		}
 partial void Insertuser(user instance);
		private void attach_users(user entity)
		{
			this.SendPropertyChanging();
			entity.usergroup = this;
		}