If your air conditioning or heating is not blowing at any speed, it could be a fuse. If it only blows on some speeds, but not others, it could be the fan blower resistor.
If you are a do-it-yourself person, you may be able to check the fuses yourself. If not, you probably need to take the car into the shop to have it looked at.
For additional assistance, please find an AskPatty Certified Repair Shop at http://www.askpatty.com/search/?type=all&m=30&q=&keyword= and they can help you diagnose and repair the problem.