Graphics card & VGA

I would appreciate some help with the following issue:

I have a second monitor connected to my laptop (through a VGA port), so that the laptop screen is mirrored. Rather than turning the second monitor on and off manually, I would like to write a program that can configure the laptop's graphics card in order to switch between the two modes (i.e., 'mirrored' mode and 'off' mode).

I haven't been able to find a way to do this yet. Any help (and code!) would be greatly appreciated!

You can probably find some code here: http://www.mentalis.org/apilist/apilist.php