--- a/include/SDL_mouse.h	Mon Aug 19 17:58:08 2002 +0000
+++ b/include/SDL_mouse.h	Mon Aug 19 18:09:44 2002 +0000
@@ -117,11 +117,15 @@
    Button 1:	Left mouse button
    Button 2:	Middle mouse button
    Button 3:	Right mouse button
+   Button 4:	Mouse wheel up	 (may also be a real button)
+   Button 5:	Mouse wheel down (may also be a real button)
  */
 #define SDL_BUTTON(X)		(SDL_PRESSED<<(X-1))
 #define SDL_BUTTON_LEFT		1
 #define SDL_BUTTON_MIDDLE	2
 #define SDL_BUTTON_RIGHT	3
+#define SDL_BUTTON_WHEELUP	4
+#define SDL_BUTTON_WHEELDOWN	5
 #define SDL_BUTTON_LMASK	SDL_BUTTON(SDL_BUTTON_LEFT)
 #define SDL_BUTTON_MMASK	SDL_BUTTON(SDL_BUTTON_MIDDLE)
 #define SDL_BUTTON_RMASK	SDL_BUTTON(SDL_BUTTON_RIGHT)