1999 volkswagon Beetle 2.0

I have a 1999 volkswagon beetle 2.0, I bought from my sister, at the time of purshase I had to jumb the car off because it had been siting for about two weeks. I drove the car home, about 10 miles, turned the engine off and tried to restart but the battery was dragging. I jumbed off again and drove the car everyday for about two weeks with no problems at all, last night I came home from work parked the car, set the alarm and this morning the car would not turn over. When the egnition switch is on I have dash lights and horn blows, I tried jumbing the car off and it still would not turn the engine over. I tried again, this time leaving the cables on for a lenght of time with the same result. Should I buy a new battery, or is there a fuse that could have blown to stop the car from turning over. Remember this car has been running perfectly, its not a piece of junk and the check engine light is not on. The alarm works it just happened like over night. PLEASE HELP ME