Error.
OKOKCANCELRETRYCANCELABORTRETRYIGNORECANCELTRYCONTINUEABORTRETRYIGNORE.
YESNOYESNOCANCELNONE. Allowed icons are:
NONEINFORMATION, ASTERISKWARNING, EXCLAMATIONERROR, HAND, STOPQUESTION, QUERYDEFBUTTON2, DEFBUTTON3,
nor DEFBUTTON4 is specified, the first button is the
default button.
Allowed options are:
DEFBUTTON2DEFBUTTON3DEFBUTTON4RIGHTTOPMOST-- Give option to quit
if RxMessageBox("Shall we continue?", "", "YesNo", "Question") = 7
then exit -- "No" button clicked, exit