private void btnEdit_Click(object sender, RoutedEventArgs e)
        {
            ToDoAddEdit addEditForm = new ToDoAddEdit(CurrentToDo, false, false);

            addEditForm.ToDoCreatedUpdated += new ToDoHandler(SyncData);
            FlyoutHelper.OpenFlyout(this, ((string)Application.Current.FindResource("Podsetnik")), 95, addEditForm);
        }
        private void btnAdd_Click(object sender, RoutedEventArgs e)
        {
            ToDoViewModel toDo = new ToDoViewModel();

            toDo.Identifier = Guid.NewGuid();
            toDo.ToDoDate   = DateTime.Now;

            ToDoAddEdit addEditForm = new ToDoAddEdit(toDo, false, true);

            addEditForm.ToDoCreatedUpdated += new ToDoHandler(SyncData);
            FlyoutHelper.OpenFlyout(this, ((string)Application.Current.FindResource("Podsetnik")), 95, addEditForm);
        }