The person resetting the light should be able to read the fault code which will tell you where the fault is. If you do not fix the fault the light will come on again.
The most common fault is the connector on the wires under the seat.
If you have unplugged them the light will stay on.
Make sure they are firmly plugged in. If you can, check the soldering as it some times fails.
There are many other possible faults, which is why the codes must be read.
Remember it is SAFE AND LEGAL to drive the car with the airbag light on. The car will NOT fail an MOT test because of it.
dd4, May 2009