Million thanks for the reply. I bought a new alarm, it works fine when I insert battery, tried and checked it by spraying some smoke on it.
But, my old alarm seems to have some wires coming out of it [of red, white and blue colors]. While the alarms I checked in the shop had no place holder for such socket. Do you know what this wires do?
I dont wanna show, but I'm really stressed out after hearing some adventurous stories from my friends.
PS: I called coupla fire alarm companies but they dont seem to understand the what am talking about.