Ford Mondeo Petrol '98 model immobiliser problems?

I have an 'R' reg Ford Mondeo SI. The electronic key doesn't work any more, but not had problems just using the 'normal' key. Until today. DOes anyone know where the master switch is to reset the immobiliser - my neighbour thinks she saw the indicators flashing late last night - and some kids running down the road ....... I know there's a master reset switch somewhere - just don't know where!