-\(By default, approximately half appear on each side.) */)
- (position, contents)
- Lisp_Object position, contents;
+\(By default, approximately half appear on each side.)
+
+If HEADER is non-nil, the frame title for the box is "Information",
+otherwise it is "Question".
+
+If the user gets rid of the dialog box without making a valid choice,
+for instance using the window manager, then this produces a quit and
+`x-popup-dialog' does not return. */)
+ (position, contents, header)
+ Lisp_Object position, contents, header;