System Information

[MidiBot at gmail.com]

 Hello. I want to write a program in which the main functionality will
depend on whether or not my
computer is connected to a power adapter(this is for laptops). I looked

in the online-documentation for this and had no luck. I imagine it is
quite easy and may even be as simple as a boolean variable...?

All I want to be able to tell is whether or not my computer is being
externally powered. More specifically
I want to be able to have my program running, and be alerted if I
un-plug my power adapter.

I am using a Mac(powerbook) with if that makes any
difference. 

Thank you very much.