The autopilot on a Boeing (and this one made in 1998, fairly new) would fly the programmed route, turns and all. It also could fly a descent if it had reached cruise altitude and had the descent programmed. At the end of the route, with no further inputs; the autopilot might kick off heading mode and it could
then circle depending on how out of trim it is by then.
Thanks for the explanation.
Like I said, I have no flying experience and my recollections were probably based on the older systems that I have seen that pretty much flew the plane on the current heading and altitude.