your right,its either the alternator or the battery,charge your battery fully,then see if it will start your car,check to see if the ignition light is on when the car runs,if it is,the the alternator,or wiring is faulty,if its not,then the battery is faulty,or you may have left a boot light on that is draining the battery,also,check to see if your battery can be topped up with water,
MM
April 2011