My car won't start & doesn't make a sound! on 2001 Hyundai Elantra

I was just driving my car 30 min ago! I then get back in the car to start it up & it doesn't start no sound no nothing. Keep in mind this is the first time this has happen! What seems to be the problem? Please help. & also doors wouldn't lock & unlock..

Asked by for the 2001 Hyundai Elantra
Sounds like your battery (at least) has failed and is not allowing even the most basic of power through. Have the battery checked; also check all connections to make sure they are secure and corrosion free.
1 more answer
The starting problem could be a dirty crank position sensor. Situated on front of engine next to bell housing. Use 10mm socket to remove holding bolt. Clean varnish build up on face of sensor with nylon scouring pad. Replace sensor and try starting. This happened to me after stopping at shop and would not start when returned.