wxMessageBox

int wxMessageBox(const wxString& message, const wxString& caption = "Message", int style = wxOK, wxWindow *parent = NULL, int x = -1, int y = -1)

General purpose message dialog. style may be a bit list of the following identifiers:

wxYES_NO	Puts Yes and No buttons on the message box. May be combined with wxCANCEL.
wxCANCEL	Puts a Cancel button on the message box. May only be combined with wxYES_NO or wxOK.
wxOK	Puts an Ok button on the message box. May be combined with wxCANCEL.
wxICON_EXCLAMATION	Displays an exclamation mark symbol.
wxICON_HAND	Displays an error symbol.
wxICON_ERROR	Displays an error symbol - the same as wxICON_HAND.
wxICON_QUESTION	Displays a question mark symbol.
wxICON_INFORMATION	Displays an information symbol.

The return value is one of: wxYES, wxNO, wxCANCEL, wxOK.

For example:

  ...
int answer = wxMessageBox("Quit program?", "Confirm",
                       wxYES_NO | wxCANCEL, main_frame);
if (answer == wxYES)
main_frame->Close();
...

message may contain newline characters, in which case the message will be split into separate lines, to cater for large messages.