How to open a car with a character

I was wondering how to change states in blender game engine for example you have a character and you want to enter inside a car or go out from the car.
please give me some answerers

I did something similar. I try to did that veary simply. It works through the near sensor. Press left mouse button to open action, when you will near the doors. Motion is with " W "

Attachments

Door 2.blend (333 KB)

thank you very muuuch