Transmission

I always took good care of my Honda Accord, but last night the transmission
wouldn't lock in at all. First there was a jerk and then the car wouldn't
move. I let it sit for a few seconds and then it would lock-in and move.
Sometimes it goes and sometimes it doesn't. I always kept the fluid changed
and this is the first problem I ever had a problem. This is '92 model with
200,000 miles. The engine still run smooth and saves gas.

Does anyone knows how to check the auto transmission to see if it is a minor
problem? If this is a costly problem, then I will just buy a new car since
it has too many miles.

Thanks,
Al