Inherited A Zapper

Hi, all. I was recently given a Super Zapper Deluxe, with two program keys (common parasites and common fungi). I received it from the friend of a friend but it came to me without an instruction booklet, so I haven't quite figured out how long I'm supposed to zap and which buttons to push first on the thing. If someone could guide me in its use, I would be so appreciative of their help. From the online research I've done, it looks like the 2003 model.

Again, thanks in advance for any help you can give!
Tukie-Tukie