Nissan Repair: my engine, nissan altima, resubmission

Question
I have a 2005 nissan altima i just recently purchased. i have noticed once i hit 70 mph my car doesn't shift. my engine sounds like it is reving up. it shifts normal until i hit the fourth gear, after that it sounds like i am in the red and if i hit 90 mph i AM in the red and my car never shifts to fith gear! what should i do? should i be worried?

Answer
Hi Val,

I am assuming this is an automatic transmission. Do you see a check engine light on? If you do then this is will tell us why it's not shifting. I didn't know Nissan came out with a 5 speed auto. Thanks for the tip. I will read up on it while I wait for your resubmission on the check engine light. Worry? ah, yeah...