private void CarEntersCarPark(object sender, EventArgs e)
{
entrySensor.carLeftSensor();
UpdateDisplay();
if (carPark.getCurrentSpaces() != 0)
{
btnCarArrivesAtExit.Show();
}
btnCarEntersCarPark.Hide();
if (carPark.getCurrentSpaces() != 5)
{
btnCarArrivesAtEntrance.Show();
}
}