auto gearbox transmission fluid

every now and then the automatic gearbox light comes on the display, and i have been told that it might be to check the level of the transmission fluid. anybody got any ideas as to how i do this without forking out garage prices and looking stupid?
thanks

1-park the car on a level surface
2-remove the filler plug on side of gearbox
3- start engine
oil should be level with filler hole so you should get a dribble of fluid when at the correct level

Pop the bonnet. There will be a dipstock for checking the auto fluid level at the back of the engine, it should have a yellow handle on the dipstick. Pull it out, while the car is off. The fluid will come up to a certain level and there will be a 'C' mark for the level the oil should be when the oil is cold. If it is low, I recommend getting an auto transmission filter change.

Driving the car with low oil will cause wear and the filter needs to be changed if you dont want the auto to destroy itself from having new oil but bits of metal in the filter destroying the auto gears.