(message-box title message parent style) -> symbol in '(ok cancel yes no)
title : string
message : string
parent = #f : frame% or dialog% object or #f
style = '(ok) : list of symbols in '(ok ok-cancel yes-no)
Displays a message to the user in a (modal) dialog, using
parent as the parent window if it is specified. The dialog's
title is title. The message string can be arbitrarily
long, and can contain explicit linefeeds or carriage returns for
breaking lines.
The style must include exactly one of the following:
- 'ok -- the dialog only has an ``Ok'' button and always
returns 'ok.
- 'ok-cancel -- the message dialog has ``Cancel'' and
``Ok'' buttons. If the user clicks ``Cancel'', the result is
'cancel, otherwise the result is 'ok.
- 'yes-no -- the message dialog has ``Yes'' and
``No'' buttons. If the user clicks ``Yes'', the result is
'yes, otherwise the result is 'no.