Nissan Repair: 01 nissan altima, nissan altima, time college student

Question
i my altima(I've had it for 6 months now) has been acting funny. I've fixed the radiator(actually put a new one in there) and now my check engine light went on and 3 weeks later the car won't start. when i took it to my mechanic he said one thing and when i took somewhere else someone told me it was the knock sensor and my thermostat that was defected and somewhere told me a water pump...i am a full time college student with little money and i put all the money i had into this car i need help. it does not want to start now...but the radio, windows, etc work but it does not want to start. If i give it a jump it will start but not on it's own
Help!!!!!

Answer
Vanessa,

Jump the car and go to Autozone or Checker and get a free charge system check and they will let you know if it is a battery or the alternator.  Second, have them check the engine code and email me back with the code and I will let you know what to do on that one.  You see, you have two things going on here.  The first is an engine management thing that is setting the code and the second is a charge problem that is either the alternator or the battery.  Looking forward to hearing from you.