Alarm

I just got a 1997 Jetta GS and I didn't know it had an alarm. I do not have a manual, nor an alarm box with the key. Last night the alarm went off when my wife unlocked the driver door. So how does the alarm system work with just a key? Also I had to disconnect the battery and now the radio display just say SAFE and the clock was reset. So how do I get the radio to work and reset the clock? Thanks in advance.

you can order a keyfob from th dealer, but the cheap way is through ebay. make sure you get an alarm keyfob with built-in uncut key. the dealer will then have to cut the key to your car, and program the alarm. these flip-keyfobs sell for around $30 at auction.