Was driving my '92 freeway speeds and without a noise my automatic transmission slipped into neutral. I pulled off the road shut it off. Restarted and it shifted into gear but would not shift into second. Going uphill pulling into a parking lot i lost power again and could not shift into any gear including reverse. Shutting off the car for 5 minutes and restarting it shifted fine. Checked the fluid level and it'* fine. Flushed the transmission fluid 7 months ago and haven't had a problem until now. I'm taking it to a mechanic, but I'm just wondering if there is something obvious i've missed. I know there are several other posts with similar problems, but I didn't see any answers.