diff -up /tmp/lsc.el.\~1\~ /tmp/lsc.el
--- /tmp/lsc.el.~1~	2011-02-21 17:22:14.214098588 +0900
+++ /tmp/lsc.el	2011-02-21 17:22:23.365735810 +0900
@@ -1,19 +1,19 @@
 (defvar list-script-chars-handler-alist nil)
 
 (define-button-type 'active-char
-  'face '(:background "gray")
+  'face '(:background "grey10")
   'action #'(lambda (button)
-	      (copy-region-as-kill (button-start button) (button-end button))))
+	      (copy-region-as-kill (button-start button) (button-end button)))
+  'help-echo #'(lambda (button)
+		 (let* ((char (char-after (button-start button)))
+			(name (get-char-code-property char 'name)))
+		   (format "U+%04X: %s" char name)))
+  'mouse-face (list :background "yellow"))
 
 (defun make-character-button (char)
   (let ((name (get-char-code-property char 'name)))
     (when name
-      (insert-text-button
-       (string char)
-       :type 'active-char
-       'help-echo (format "U+%04X: %s" char name)
-       ;; We must make this list each time to highlight only one character.
-       'mouse-face (list :background "yellow")))))
+      (insert-text-button (string char) :type 'active-char))))
 
 ;; List characters in RANGE in the current buffer assuming that the
 ;; window width is 80, and tab-width is set to 4.