--- a/include/SDL_mouse.h	Sat Dec 29 03:25:11 2007 +0000
+++ b/include/SDL_mouse.h	Sat Dec 29 06:09:25 2007 +0000
@@ -207,9 +207,13 @@
 #define SDL_BUTTON_LEFT		1
 #define SDL_BUTTON_MIDDLE	2
 #define SDL_BUTTON_RIGHT	3
+#define SDL_BUTTON_X1		4
+#define SDL_BUTTON_X2		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)
+#define SDL_BUTTON_X1MASK	SDL_BUTTON(SDL_BUTTON_X1)
+#define SDL_BUTTON_X2MASK	SDL_BUTTON(SDL_BUTTON_X2)
 
 
 /* Ends C function definitions when using C++ */