diff --git a/src/web/client/typing_practice.html b/src/web/client/typing_practice.html
index 36fd8af..e344f3c 100644
--- a/src/web/client/typing_practice.html
+++ b/src/web/client/typing_practice.html
@@ -43,7 +43,7 @@
 
 		<!-- library source files -->
 		<!-- <script src="../../game/lib/keyboard_shortcut.js"></script> -->
-		<script src="../../game/lib/util/string_util.js"></script>
+		<script src="../../game/lib/util/string_util.js?update_date=190517"></script>
 		<script src="../../game/lib/util/number_util.js"></script>
 		<script src="../../game/lib/util/record_util.js"></script>
 
@@ -85,18 +85,18 @@
 
 		<!-- Test typing : source files -->
 		<script src="../../game/typing/lib/typing_text_manager.js"></script>
-		<script src="../../game/typing/lib/typing_content_bg.js"></script>
+		<script src="../../game/typing/lib/typing_content_bg.js?update_date=190517"></script>
 		<script src="../../game/typing/lib/key_mapper.js"></script>
 		<script src="../../game/typing/lib/key_button.js"></script>
-		<script src="../../game/typing/lib/hand.js"></script>
-		<script src="../../game/typing/lib/keyboard.js"></script>
+		<script src="../../game/typing/lib/hand.js?update_date=190517"></script>
+		<script src="../../game/typing/lib/keyboard.js?update_date=190517"></script>
 		<script src="../../game/typing/lib/animal.js?update_date=191224"></script>
-		<script src="../../game/typing/lib/animal_list.js?update_date=191224"></script>
+		<script src="../../game/typing/lib/animal_list.js?update_date=190517"></script>
 
 		<script src="../../game/typing/practice/define_variables.js"></script>
 		<script src="../../game/typing/practice/typing_score.js"></script>
 		<script src="../../game/typing/practice/loading.js"></script>
-		<script src="../../game/typing/practice/game.js?update_date=191225"></script>
+		<script src="../../game/typing/practice/game.js?update_date=190517"></script>
 		<script src="../../game/typing/practice/main.js"></script>
 
 
diff --git a/src/web/client/typing_test.html b/src/web/client/typing_test.html
index 7a1d3ba..15befee 100644
--- a/src/web/client/typing_test.html
+++ b/src/web/client/typing_test.html
@@ -42,7 +42,7 @@
 		<script src="../../game/lib/global/global_variables.js?update_date=191224"></script>
 
 		<!-- library source files -->
-		<script src="../../game/lib/util/string_util.js"></script>
+		<script src="../../game/lib/util/string_util.js?update_date=190517"></script>
 		<script src="../../game/lib/util/number_util.js"></script>
 		<script src="../../game/lib/util/record_util.js"></script>
 
@@ -84,18 +84,18 @@
 		<!-- Test typing : source files -->
 		<script src="../../game/typing/lib/content_progress.js"></script>
 		<script src="../../game/typing/lib/typing_text_manager.js"></script>
-		<script src="../../game/typing/lib/typing_content_bg.js"></script>
-		<script src="../../game/typing/lib/key_mapper.js?update_date=190515"></script>
+		<script src="../../game/typing/lib/typing_content_bg.js?update_date=190517"></script>
+		<script src="../../game/typing/lib/key_mapper.js"></script>
 		<script src="../../game/typing/lib/key_button.js"></script>
-		<script src="../../game/typing/lib/hand.js?update_date=190515"></script>
-		<script src="../../game/typing/lib/keyboard.js?update_date=190515"></script>
+		<script src="../../game/typing/lib/hand.js?update_date=190517"></script>
+		<script src="../../game/typing/lib/keyboard.js?update_date=190517"></script>
 		<script src="../../game/typing/lib/animal.js?update_date=191224"></script>
-		<script src="../../game/typing/lib/animal_list.js?update_date=191224"></script>
+		<script src="../../game/typing/lib/animal_list.js?update_date=190517"></script>
 
 		<script src="../../game/typing/test/define_variables.js"></script>
-		<script src="../../game/typing/test/loading.js"></script>
+		<script src="../../game/typing/test/loading.js?update_date=190517"></script>
 		<script src="../../game/typing/test/average_typing_speed.js"></script>
-		<script src="../../game/typing/test/game.js?update_date=191225"></script>
+		<script src="../../game/typing/test/game.js?update_date=190517"></script>
 		<script src="../../game/typing/test/main.js"></script>