is it xenon lights? if it is then it will be the ignitor unit under the headlamp assembly...get a manual and find out how to remove the headlamp (tricky)and get an ignitor unit (metal box under headlamp and plugged into bulb) from ebay £30. chuck old one away and silicon the new one in its place. the bulbs last forever and ignitor units fail all the time.
david
April 2011