Keyfob unlocking & windows

I tried to unlock my passenger side with the keyfob yesterday but it is not working anymore? What is the problem? Also I can put the windows down but they roll right back up in 2 seconds? What should I do?

Need some more info. What year? How many miles? bla bla...

The key problem may just be that your key is so warn, and your door lock hardly used, that it just plain dosent work.

It's a 2003 with 66000 miles on it. The lock was working fine before it just stopped working from the keyfob yesterday but the door unlocks normally when I hit the automatic unlock on the door panel or if I manually unlock it. If it is worn, what can I do to fix it?

Lock cant be worn out yet. Maybe bad sw alignment inside door mech.

If all started simultaneously, then this may also be pinched/broken harness -or- water leak into connectors/ctrl box causing all this fun. Door paneling and/or ctrl box has to be opened for inspection. Check this link: http://www.cardomain.com/ride/748507/13

So, the locks started working again on the keyfob. The windows roll down normally but then the windows didn't roll up automatically when car shuts off. I didn't have a problem with that.
Today, I go out and then I put my windows up, shut off the ignition and the windows roll down? That has happened all day. I went to the Nissan Dealer and they said either there is moisture in the (don't remember the name) or it needs to be replaced. This part cost $60 and $210 for labor the guy told me.
I want to do it myself but before I do anything what do you guys think?

...I want to do it myself but before I do anything what do you guys think?

As explained on the web page... "may also be pinched/broken harness -or- water leak"

Seek cause for leak and seal, DIY dry

It all depends on what the part is and where it is located. you can do anything yourself if you have the tools, time, and some kind of mechanical ability.