problem starting
 

Having trouble starting my 2002audi a4 Quattro 3.0. After massive blizzard in which the car performed excellent. I tried to start the car and nothing happened. Lights and dash lit up. The battery is only 6 months old. Just purchased a new starter and had it put in. The car will still will not start, only clicks one time. Mechanic can not tell me why it won't start. He says he's going to check the fuses and relays. Any advice