Car Alarms: alarm disarm feature or electrical on 98 mazda Protege?, mazda protege, dash lights

Question
The other day I turned off my 98 mazda protege to get my mail.I came back and turned the key and the nothing even happened. The key would turn but thats it. We first tried to jump start it then replaced the battery after we found out it was dead. But the car will still not even attempt to start. The headlights turn on with the new battery but all the electrical in the car is shut off.  There is an old alarm in the car and someone told me that the alarm might have disabled the car when we attempted the jump start. Even the alarm light doesnt blink. All the electrical is dead except for the headlights. If it is the alarm disabling feature what can I do to fix this? If its not what else can it be?
Thanks
Matt

Answer
This car does not have a factory alarm so it is an aftermarket system holding you up. However...
...I am troubled by the "but all the electrical in the car is shut off." statement.

No power at all? No radio no dash lights? nothing?

If that's the case, the trouble is not the alarm,
it's your charging system. The alternator not right.

Have the mechanic check your charging system here
because if it was the alarm, all the power would work,
but the starter kill (if installed) was the problem
the starter would be the only thig that's  dead.

So I suggest you look at this first.

Let me know what you find.

ALARMTEK