try this, it my need a few attempts...
switch ignition on..when ever airbag light goes off turn ignition off for 4 seconds then turn back on...repeat this a further 3times....after 4th time turn ignition on for 1second then off and start engine..airbag light should be reset..
Also for info try these links..
http://www.almeraownersclub.com/
http://www.clubnissan.co.uk/forum/
rob, July 2010