ActionScript for Flash MX: The Definitive Guide, 2nd Edition By Colin Moock
Chapter 18. ActionScript Language Reference
capabilities.input Property
Flash 6
the user input device for the system
read/write
System.capabilities.input
Description
The string input property indicates the type of input device provided by the system hardware. For mouse-style devices, the type is "point". Other names for input devices, such as a stylus or a cursor pad on a cell phone, will be determined as they become available. The input property allows a movie to switch to, say, a custom made keypad-only input mode, which would be much more limited than the typical mouse input mode.
The corresponding server string for input is I, with possible values of point and other input device names to be determined. See capabilities.serverString for details.