|str||The name of the option to add to the charm.|
|callback||The script (or URL) to run if pressed.|
When you move your mouse to the top right, or bottom right,
corner of the screen in Windows 8 you get a slide-out menu of
"charms". These are special global icons that reference certain
aspects of the OS. This function can be used to add your own
options to the "charm" labelled as "Settings".
The first argument is the name of the option you are adding as a string, and the second argument is the script from your game that you wish the new option to access, or a URL that you wish the charm to open. If you choose a URL then it should be a string and start with http://, for example "http://www.google.co.uk".
The above code will add an option to the Settings "charm" called "Controls", and when it is selected it will run the script "scr_GameControls".