is it possible to add triggers/sensors

I just purchased a '96 sentra from my uncle and it has an alarm system.  My problem is I have no idea what type of alarm it is and secondly, the alarm is not set to go off w/the trunk.  My question is, can i add a trigger/sensor to my trunk so that it will go off when it is opened?  If so, how?

Possibly just tie a wire from your trunk pin switch to your door light switch so the alarm will think a door has opened but it will be the trunk.Your inside domelight will come on when you open your trunk but it should be ok.Also make sure they are the same polarity (Trunk and door pin switch.)

thanks for the advice, my problem is I have the slightest clue on what a pin switch is or where to even find it.   I'm a newcomer in regards to alarm systems.  is this something I can do, or should i have a pro do this.  I appreciate any help

I would suggest a pro then to do this.They more than likey want to sell you a whole new alarm system and that is not what you need.Ask if they would simply tie your trunk pin switch into your door pin wire so when the trunk is open it sends power to your alarm system then your alarm system will think that your door is open.So maybe a small time shop would do this by the hour or something like that and be better for you. Let me know how it works out