void AddUser(object parameter)
 {
     SelectedPerson = null; // Unselects last selection. Essential, as assignment below won't clear other control's SelectedItems
     var person = new PocoPerson();
     SelectedPerson = person;
 }
 public void DeletePerson(PocoPerson person)
 {
     People.Remove(person);
     OnPeopleChanged();
 }
        public void UpdatePerson(PocoPerson person)
        {

        }
 public void AddPerson(PocoPerson person)
 {
     People.Add(person);
     OnPeopleChanged();
 }