patch 7.4.793
Problem:    Can't specify when not to ring the bell.
Solution:   Add the 'belloff' option. (Christian Brabandt)
diff --git a/src/proto/misc1.pro b/src/proto/misc1.pro
index 5df81c9..96b0572 100644
--- a/src/proto/misc1.pro
+++ b/src/proto/misc1.pro
@@ -49,7 +49,7 @@
 int prompt_for_number __ARGS((int *mouse_used));
 void msgmore __ARGS((long n));
 void beep_flush __ARGS((void));
-void vim_beep __ARGS((void));
+void vim_beep __ARGS((unsigned val));
 void init_homedir __ARGS((void));
 void free_homedir __ARGS((void));
 void free_users __ARGS((void));