I replaced my battery last night and now neither of my two keychain remote door lock-unlock things don't work. What should I look at to solve this?

Thanks!

New info, but still not solved:

Ford dealer told me that they lost programming. He said to get in the car and turn the key on and off on and off 7-8 times until the door locks unlock, which puts them into Programming Mode.

He said I'd have about 5 seconds to push a button on the remotes and that should reset them to work.

I tried it, and as he said, after 7-8 times turning the key on & off, the doors locked, but I pushed the button on the remotes and they still don't work.

Issue Solved. Yay!

Previously, I did the key back and forth thing with the door closed. I tried it with the door open and it worked like a charm.

Sweeeet!