how do i shut this alarm off?

ok heres the deal my girlfriend has an after market alarm on her car, i dont know what brand of alarm but it has an amber colored button/light on the dash, and a black button under the dash, today the amber button/ light on the dash got pressed and the car was fine, after we tried to move the car the alarm freaked out and would not stfu. she did not get a key fob with the car when she bough it, she just has a metal key, so i disconnected the battery and the alarm shut up, so i left it off for a few mins and when i put it back the alarm freaks again....so i called my friend who knows a lil about alarm and he said turn key on, press button under dash, turn key off, alarm will die, so i did and the alarm shut off, car was fine for about 10 mins, then freaked out again....i do not know what to do with it. we cannot drive the car....how do i shut this thing up? help is desperately needed..thanks guys....

What kind of car is it if you look under the dash you can maybe see some fusing if you remove the fuse the car should be fine

Follow the wire from the siren.  It WILL lead you to the alarm brain.  Unplug the brain.