1997 Chrysler LHS car alarm

I have a 94 lhs, but I have had my alarm go off when I lock the doors with the key and then reach in through a open window and open the door and try to start the car.
My cars anti theft system is meant to keep someone from actually starting and driving off with the car by shutting off the gas to the engine when the alarm goes off.
Please bare in mind that the 96 and the 94 are different systems.
Can you order a new key fob from a dealer?
Hope this helps.