--- a/.emacs-my	Sun Oct 23 21:55:13 2011 +0300
+++ b/.emacs-my	Sun Oct 23 22:05:48 2011 +0300
@@ -33,17 +33,23 @@
 ;; Shut off message buffer by setting nil.
 (setq message-log-max 512)
 
-;; Set the debug option to enable a backtrace when a problem occurs.
-(setq debug-on-error nil)               ; t/nil
-(setq debug-on-signal nil)
-
-;; Get trace when press C-g.
-(setq debug-on-quit nil)                ; t/nil
-
 ;; Prevent Emacs from loading 'default.el', which loaded after '.emacs'.
 ;; Also '-q' prevent loading your init file.
 (setq inhibit-default-init nil)         ; t/nil
 
+(defun my-debug (mode)
+  "With prefix enable debug backtrace when problems occur else disable."
+  (interactive "P")
+  (when mode
+    (setq mode t))
+  (setq debug-on-error mode)
+  (setq debug-on-signal mode)
+  ;; Get trace when press C-g.
+  (setq debug-on-quit mode)
+  )
+
+(my-debug nil)
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (message "user info")