Petrol or diesel?
Any flashing lights on dash?
Was it running ok before?
When it is turning over does it sound different, faster or slower?
Have you checked the cam belt?
Are you sure it has fuel?
Does any one else have access to the car? I know of one where it turned out the owners son had used her car to jump start his own, did it wrong and fried her electrics.
vic, November 2009