Note that input_to is non-blocking which means that the object calling input_to does not pause waiting for input. Instead the object continues to execute any statements following the input_to. The specified function 'fun' will not be called until the user input has been collected.
If "input_to()" is called more than once in the same execution, only the first call has any effect.
If optional argument `flag' is non-zero, the line given by the player will not be echoed, and is not seen if snooped (this is useful for collecting passwords).
The function 'fun' will be called with the user input as its first argument (a string). Any additional arguments supplied to input_to will be passed on to 'fun' as arguments following the user input.