--- a/lisp/prim/scrollbar.el	Mon Aug 13 09:00:04 2007 +0200
+++ b/lisp/prim/scrollbar.el	Mon Aug 13 09:02:59 2007 +0200
@@ -14,9 +14,8 @@
 ;; General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with XEmacs; see the file COPYING.  If not, write to the 
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 
 ;;; Synched up with: Not in FSF. (Completely divergent from FSF scroll-bar.el)
 
@@ -40,7 +39,8 @@
 This is the little arrow to the left of the scrollbar.  One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window (- (window-hscroll window) 1))
     (setq zmacs-region-stays t)
     nil))
@@ -50,7 +50,8 @@
 This is the little arrow to the right of the scrollbar.  One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window (+ (window-hscroll window) 1))
     (setq zmacs-region-stays t)
     nil))
@@ -60,7 +61,8 @@
 \(The way this is done can vary from scrollbar to scrollbar.\) One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window (- (window-hscroll window)
 				     (- (window-width window) 2)))
     (setq zmacs-region-stays t)
@@ -71,7 +73,8 @@
 \(The way this is done can vary from scrollbar to scrollbar.\) One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window (+ (window-hscroll window)
 				     (- (window-width window) 2)))
     (setq zmacs-region-stays t)
@@ -82,7 +85,8 @@
 \(The way this is done can vary from scrollbar to scrollbar.\). One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window 0)
     (setq zmacs-region-stays t)
     nil))
@@ -92,7 +96,8 @@
 \(The way this is done can vary from scrollbar to scrollbar.\). One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (when (window-live-p window)
+  (if (not (window-live-p window))
+      nil
     (scrollbar-set-hscroll window 'max)
     (setq zmacs-region-stays t)
     nil))
@@ -103,8 +108,9 @@
 representing how many columns the thumb is slid over.  You can advise
 this function to change the scrollbar behavior."
   (let ((window (car data))
-	(value  (cdr data)))
-    (when (and (window-live-p window) (integerp value))
+	(value (cdr data)))
+    (if (not (or (window-live-p window) (integerp value)))
+	nil
       (scrollbar-set-hscroll window value)
       (setq zmacs-region-stays t)
       nil)))