This prompts the user with the specified message, to which they have a choice of responses. If the user responds Yes, the given variable is set to 1. If the user instead responds No, the given variable is set to 0.
This prompts the user with the message given, for example:
message(A, "Would you like planet Earth to blow up?")
There is an optional 'yesno' value which specifies which button is highlighted by default:
0 or not specified, this will highlight the 'No' option:
1, this will highlight the 'Yes' option:
This highlighting determines which response will be 'assumed' if the user presses Return.
Specifics
RISC OS does not support escaped characters (i.e. the '\"') and it does not support the optional 'yesno' value, this would be ignored.
Furthermore, the RISC OS buttons are OK (equivalent to 'Yes', and actioned if 'Return' is pressed), and Cancel (equivalent to 'No', and actioned if 'Escape' is pressed).
It is worth keeping this in mind in order to avoid complications such as the following:
