diff -Naur xfwm4/src/client.c sm_ok/src/client.c
--- xfwm4/src/client.c	2005-01-19 21:35:22.000000000 +0100
+++ sm_ok/src/client.c	2005-01-21 20:54:31.000000000 +0100
@@ -2317,6 +2317,40 @@
     }
     clientRaise (c);
 }
+///////flw1
+long f_step= 0x16000000;
+long f_min = 0x40000000;
+
+void
+clientDecOpacity (Client * c)
+{
+	ScreenInfo *screen_info = NULL;
+DisplayInfo *display_info = NULL;
+screen_info = c->screen_info;
+display_info = screen_info->display_info;
+   if ( c->opacity > f_min )
+   {
+	c->opacity -= f_step;
+	compositorWindowSetOpacity (display_info, c->frame, c->opacity);
+   }
+}
+
+void
+clientIncOpacity (Client * c)
+{
+ScreenInfo *screen_info = NULL;
+DisplayInfo *display_info = NULL;
+screen_info = c->screen_info;
+display_info = screen_info->display_info;
+   if ( c->opacity < NET_WM_OPAQUE )
+   {
+	c->opacity += f_step;
+	if ( c->opacity < f_min )
+	c->opacity = NET_WM_OPAQUE ;
+	compositorWindowSetOpacity (display_info, c->frame, c->opacity);
+
+   }
+}
 
 void
 clientShade (Client * c)
diff -Naur xfwm4/src/compositor.c sm_ok/src/compositor.c
--- xfwm4/src/compositor.c	2005-01-17 22:00:57.000000000 +0100
+++ sm_ok/src/compositor.c	2005-01-21 20:10:58.000000000 +0100
@@ -760,7 +760,7 @@
                 double opacity = SHADOW_OPACITY;
                 if (cw->mode == WINDOW_TRANS)
                 {
-                    opacity = opacity * ((double) cw->opacity) / ((double) NET_WM_OPAQUE);
+                    opacity = opacity * ((double) cw->opacity) / ((double) NET_WM_OPAQUE) * ((double) cw->opacity) / ((double) NET_WM_OPAQUE);
                 }
                 cw->shadow = shadow_picture (screen_info, opacity,
                                              cw->attr.width + 2 * cw->attr.border_width,
diff -Naur xfwm4/src/events.c sm_ok/src/events.c
--- xfwm4/src/events.c	2005-01-12 18:49:41.000000000 +0100
+++ sm_ok/src/events.c	2005-01-21 20:10:58.000000000 +0100
@@ -776,19 +776,23 @@
     }
     else if (ev->button == Button4)
     {
-        /* Mouse wheel scroll up */
+	clientIncOpacity(c);
+
+        /* Mouse wheel scroll up 
         if (!FLAG_TEST (c->flags, CLIENT_FLAG_SHADED))
         {
             clientShade (c);
-        }
+        }*/
     }
     else if (ev->button == Button5)
     {
-        /* Mouse wheel scroll down */
+	clientDecOpacity(c);
+
+        /* Mouse wheel scroll down 
         if (FLAG_TEST (c->flags, CLIENT_FLAG_SHADED))
         {
             clientUnshade (c);
-        }
+        }*/
     }
 }