Hyundai Repair: 1999 hyundia tiburon, range switch, hyundia

Question
my car was running fine.  i stopped to pick some one up.  we i left the car wouldn't go over 30mph and the rpm were reving up like the car was in neutral. i parked the car and waited for my dad to get home.  about 1 1/2hrs.  he rove the car down the road and said that he didn't see nothing wrong with it.  so i drove it approx. 20 miles. i then parked the car.  30 mins later when i was ready to leave the gear shift would move into gear but the car would not move.in any direction (FWD, REV)it was like it is trying to go but wont. when i put the car in gear and push the gas it is like its in neutral. also my dad jacked it up to check it out and the wheels will turn while in park. PLEASE HELP ME  

Answer
Start by checking your transmission fluid.  If it's low, add the appropriate amount of SP-III transmission fluid and recheck.

If the problem is occuring with the proper amount of transmission fluid, you may have a faulty or misadjusted shift cable or range switch, but it's much more likely that you'll need to overhaul or replace your transmission.