--- a/lisp/prim/scrollbar.el	Mon Aug 13 09:15:13 2007 +0200
+++ b/lisp/prim/scrollbar.el	Mon Aug 13 09:15:49 2007 +0200
@@ -14,21 +14,23 @@
 ;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; along with XEmacs; see the file COPYING.  If not, write to the 
+;; Free Software Foundation, 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
 
 ;;; Synched up with: Not in FSF. (Completely divergent from FSF scroll-bar.el)
 
 (defun init-scrollbar-from-resources (locale)
-  (if (and (featurep 'x)
-	   (or (eq locale 'global)
-	       (eq 'x (device-or-frame-type locale)))
-	   (x-init-scrollbar-from-resources locale))))
+  (when (and (featurep 'x)
+	     (or (eq locale 'global)
+		 (eq 'x (device-or-frame-type locale))))
+    (x-init-scrollbar-from-resources locale)))
 
 ;;
 ;; vertical scrollbar functions
 ;;
 
+;;; ### Move functions from C into Lisp here!
 
 ;;
 ;; horizontal scrollbar functions
@@ -39,8 +41,7 @@
 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."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window (- (window-hscroll window) 1))
     (setq zmacs-region-stays t)
     nil))
@@ -50,8 +51,7 @@
 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."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window (+ (window-hscroll window) 1))
     (setq zmacs-region-stays t)
     nil))
@@ -61,8 +61,7 @@
 \(The way this is done can vary from scrollbar to scrollbar.\) One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window (- (window-hscroll window)
 				     (- (window-width window) 2)))
     (setq zmacs-region-stays t)
@@ -73,8 +72,7 @@
 \(The way this is done can vary from scrollbar to scrollbar.\) One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window (+ (window-hscroll window)
 				     (- (window-width window) 2)))
     (setq zmacs-region-stays t)
@@ -85,8 +83,7 @@
 \(The way this is done can vary from scrollbar to scrollbar.\). One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window 0)
     (setq zmacs-region-stays t)
     nil))
@@ -96,8 +93,7 @@
 \(The way this is done can vary from scrollbar to scrollbar.\). One argument is
 passed, the scrollbar's window.  You can advise this function to
 change the scrollbar behavior."
-  (if (not (window-live-p window))
-      nil
+  (when (window-live-p window)
     (scrollbar-set-hscroll window 'max)
     (setq zmacs-region-stays t)
     nil))
@@ -108,9 +104,8 @@
 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)))
-    (if (not (or (window-live-p window) (integerp value)))
-	nil
+	(value  (cdr data)))
+    (when (and (window-live-p window) (integerp value))
       (scrollbar-set-hscroll window value)
       (setq zmacs-region-stays t)
       nil)))