Meltz

So today I was changing out the battery connectors and when I connected the new ones, an alarm started going off. I found a little black button near the fuse box under the steering wheel, held it down, and turned the key to the ACC position. This seemed to have done the trick, but I only hope I didn't piss off the neighbors.

So I have a couple of questions. First of all, why did the alarm go off tonight, but not when I locked the keys in the truck the other day? When I did that, I had to pry open the top corner of the passenger door and use a hangar to unlock the door. I would think that would set an alarm off. Does it need to be enabled or something?

Second of all, do you guys know if there's any sort of remote I can buy to use with this thing? It'd be nice not to have to do that whole button-key thing.
Thanks!