The Control method show-dialog will bring up a dialog with the options "yes" and "no". The arguments passed to the method will specify the title, message, and text for both the "yes" and "no" buttons. The method returns 1 if the "yes" button is clicked, and 0 otherwise.
This method only produces a "true" dialog with the Mac OS X application. With the command line version of breve, this method will produce a message to standard output.