Disable Key-Fob Door Locking???

I've looked through the owners manual; it's not there...

Here's the story: I'm going into my house, the back door is locked...My arms are full of groceries, I fumble in my shirt pocket for my keys...My 2002 Xterra SE starts beeping and lights flashing...I get my groceries put down, go back out, and unlock the doors and finish unloading...

Now, whenever I leave the Xterra, it locks itself up... :banghead:

Somehow, I activated some code to self-lock when left unattended...

I don't want that...

So, I want to erase all codes in memory for the door locks/anti-theft system...

I tried unhooking the battery for a couple hours...Didn't work...

How do I wipe out the codes and reset the system to the default???