private void MainForm_Load(object sender, EventArgs e) { customerListBox.DataSource = _customerController.GetAll(); bookingsListbox.DataSource = _bookingController.GetAllActive(); availableRoomsListbox.DataSource = _hotelRoomController.GetAllAvailable(); customerListBox.SelectedIndex = -1; bookingsListbox.SelectedIndex = -1; availableRoomsListbox.SelectedIndex = -1; }