Constraits Tutorial/Sample

Is there any sample or tutorial for creating constraits?
I know some basic physics, but I dont know how to do constraits.

Ventilator's car script can be found here:
http://www.conitecserver.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=32;t=000006

It uses PH_WHEEL and there is an example of a PH_HINGE a little farther in the topic.

Jason

Mmh thx, but I does'nt help really.To hard to learn how it works with such a big code.The little script said nothing on how it works.
Maybe someone could write a simple explaination how 2 or 3 objects can become stuck together?!

Hello Delivery,
the Ventilator's car script work only with A6 Pro...because the script use many objects physic entitys.