Security System

I have a 2003 Tacoma and I can lock my doors. The only problem is wether I use the auto door lock remote or the key to unlock the door the alarm (horn) goes off for an ungodly amount of time till it stops. Ive tried using the key in the locks, locking and unlocking with the remote but nothing seems to help. So, I haven't been locking my truck. Does anyone know how to fix this thing? I don't really care if I disable it, no one pays any attention to car alarms anymore anyway.

THanks

I am not sure if you have some sort of passlock on your truck. Will you truck start with the alarm going off?

Yes, the truck starts and runs fine, you just have to listen to the stupid horn for about 5 minutes. No pass lock.