Volkswagen Repair: 98 cabrio gear shift, gear shift, safety concern

Question
I have a '98 cabrio with about 64,000 miles on it. This morning I started the car with no problem, but the button on the gear shift would not depress, so I could not put it into gear. It's an automatic, and the steering was not locked. There was no problem with the parking break. I live in Chicago, so it is cold. Could something be frozen? Could I just be low on transmission fluid or anti-lock brake fluid? Or do you think this is a more serious problem? Thank you for any advice you have.

Answer
I am more apt to think it is something in the shifter stick itself.  The linkage within is binding somewhere due to wear - so the only thing you can do is take it apart and take a look.  Low fluid?  Check your manual to see what it says if the fluid gets too low, but I see that more of a safety concern not to lock it up like that.  Still...  Brakes, no.  can't help any more than that.  If you want more info pose the question on vwvortex.com where there are owners and mechanics