No, pull out one is in the Astra F, the 99 model is an Astra G - see below :
Its the button in the middle.
If you push it and the orange LED does not come on stop, switch off the car, wait 5 seconds and start it up again.
If it still does not come on the aircon compressor's clutch (disengages it when you accelerate hard) has broken and needs to be fixed.