citreon car air bag light stays on some time

Get it checked out at a garage.

check the wires under the passenger seat,the connectors dry out witch causes the light to come on now and again

Take it to citreon, they may have have a look at it for free.

With the newer citroens there is a airbag key in the drivers side door try resetting the key and turn it back to on position should solve it ;-)

It is French - the electrics are supposed to be rubbish

It is a common problem with some Citroens and some Peugeots and is usually an iffy connection for the drivers seat side airbag. there is a connector under the seat base which sometimes is spasmodically iffy.
Fitting a new connector (or probably soldering the wires) will usually cure the problem. BUT remember you MUST disconnect the battery, remove the airbag circuit Fuse and wait at least 5 minutes before working on the wiring.