diff --git a/src/game/lib/keyboard_shortcut.js b/src/game/lib/keyboard_shortcut.js
index 02956f9..3ceb5ae 100644
--- a/src/game/lib/keyboard_shortcut.js
+++ b/src/game/lib/keyboard_shortcut.js
@@ -1,8 +1,5 @@
 function KeyboardShortcut() {
-	console.log("KeyboardShortcut");
-
 	this.keyHandlerMapper = {};
-	console.log(this.keyHandlerMapper[Phaser.KeyCode.ESC]);
 
 	game.input.keyboard.addCallbacks(this, this.keyDown, this.keyUp, null);
 };
diff --git a/src/game/menu/menu_app.js b/src/game/menu/menu_app.js
index e6f9ae3..4c01650 100644
--- a/src/game/menu/menu_app.js
+++ b/src/game/menu/menu_app.js
@@ -32,12 +32,18 @@ var MenuApp = {
 		);
 
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"menu_app"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			sessionStorageManager.clear();
-			location.href = '../../web/client/login.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 
@@ -62,6 +68,10 @@ var MenuApp = {
 	},
 
 
+	back: function() {
+		sessionStorageManager.clear();
+		location.href = '../../web/client/login.html';
+	},
 
 	loadAppData: function() {
 		var dbConnectManager = new DBConnectManager();
diff --git a/src/game/menu/menu_typing_practice.js b/src/game/menu/menu_typing_practice.js
index 2486288..075546d 100644
--- a/src/game/menu/menu_typing_practice.js
+++ b/src/game/menu/menu_typing_practice.js
@@ -39,6 +39,7 @@ var MenuTypingPractice = {
 		// );
 
 
+		// keyboard shortcut
 		this.keyboardShortcut = new KeyboardShortcut();
 		this.keyboardShortcut.addCallback(
 			Phaser.KeyCode.ESC,	// keyCode
@@ -82,11 +83,11 @@ var MenuTypingPractice = {
 		this.makeActiveTypingPracticeAppButtons();
 	},
 
+
 	back: function() {
 		location.href = '../../web/client/menu_app.html';
 	},
 
-
 	makeActiveTypingPracticeAppButtons: function() {
 		var dbConnectManager = new DBConnectManager();
 		dbConnectManager.requestTypingPracticeAppList(
diff --git a/src/game/menu/menu_typing_test.js b/src/game/menu/menu_typing_test.js
index 73cfa31..42db56c 100644
--- a/src/game/menu/menu_typing_test.js
+++ b/src/game/menu/menu_typing_test.js
@@ -39,11 +39,18 @@ var MenuTypingTest = {
 		// );
 
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"menu_typing_test"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			location.href = '../../web/client/menu_app.html';
-		});
+		screenTopUI.makeBackButton( function() { (function() { this.back(); }).bind(this) });
 		screenTopUI.makeFullScreenButton();
 
 
@@ -77,6 +84,10 @@ var MenuTypingTest = {
 	},
 
 
+	back: function() {
+		location.href = '../../web/client/menu_app.html';
+	},
+
 	makeActiveTypingTestAppButtons: function() {
 		var dbConnectManager = new DBConnectManager();
 		dbConnectManager.requestTypingTestAppList(
diff --git a/src/game/mouse/space_invaders/game.js b/src/game/mouse/space_invaders/game.js
index faf16bc..01981cf 100644
--- a/src/game/mouse/space_invaders/game.js
+++ b/src/game/mouse/space_invaders/game.js
@@ -10,12 +10,18 @@ var Game = {
 			(function() { this.gameOver(); }).bind(this)
 		);
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"space invaders"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			sessionStorageManager.resetPlayingAppData();
-			location.href = '../../web/client/menu_app.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 		var scoreBoard = new ScoreBoard();
@@ -83,6 +89,12 @@ var Game = {
 		// this.countDown();
 	},
 
+
+	back: function() {
+		sessionStorageManager.resetPlayingAppData();
+		location.href = '../../web/client/menu_app.html';
+	},
+
 	initListeners: function() {
 	},
 
diff --git a/src/game/ranking/ranking.js b/src/game/ranking/ranking.js
index ba1ccc3..67b222d 100644
--- a/src/game/ranking/ranking.js
+++ b/src/game/ranking/ranking.js
@@ -19,11 +19,18 @@ var Ranking = {
 		// phaser.alpha = 0.1;
 
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"ranking"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			location.href = '../../web/client/start.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 
@@ -69,6 +76,11 @@ var Ranking = {
 		game.time.events.loop(Phaser.Timer.SECOND * 10, this.getRecordToRankingServer, this);
 	},
 
+
+	back: function() {
+		location.href = '../../web/client/start.html';
+	},
+
 	makeTextButton: function(x, y, buttonText, eventListener) {
 		var setting = new RoundRectButtonSetting(x, y, 200, 100);
 		setting.fontStyle.fontWeight = "bold";
diff --git a/src/game/result/result.js b/src/game/result/result.js
index 6b8b500..4e1cd1b 100644
--- a/src/game/result/result.js
+++ b/src/game/result/result.js
@@ -16,18 +16,24 @@ var Result = {
 		this.game.stage.backgroundColor = '#4d4d4d';
 		this.chartGraphics = game.add.graphics(100, game.world.height - 120);
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"result"	// callerClassName
+		);
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ENTER,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.restartStage(); }).bind(this),	// keyUpHandler
+			"result"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			if(isTypingPracticeApp())
-				location.href = '../../web/client/menu_typing_practice.html';
-			else if(isTypingTestApp())
-				location.href = '../../web/client/menu_typing_test.html';
-			else
-				location.href = '../../web/client/menu_app.html';
-
-			sessionStorageManager.resetPlayingAppData();
-		});
+		screenTopUI.makeBackButton( function() { (function() { this.back(); }).bind(this) });
 		screenTopUI.makeFullScreenButton();
 
 
@@ -54,6 +60,18 @@ var Result = {
 		screenBottomUI.printRightText(sessionStorageManager.getPlayerName());
 	},
 
+
+	back: function() {
+		if(isTypingPracticeApp())
+			location.href = '../../web/client/menu_typing_practice.html';
+		else if(isTypingTestApp())
+			location.href = '../../web/client/menu_typing_test.html';
+		else
+			location.href = '../../web/client/menu_app.html';
+
+		sessionStorageManager.resetPlayingAppData();
+	},
+
 	printRecord: function() {
 		const style = { font: "bold 38px Arial", fill: "#fff", align: "left", boundsAlignH: "center", boundsAlignV: "middle" };
 		var titleText = game.add.text(game.world.width / 2, 35, "결과", style);
diff --git a/src/game/start/start.js b/src/game/start/start.js
index a640b45..05e2c7f 100644
--- a/src/game/start/start.js
+++ b/src/game/start/start.js
@@ -12,18 +12,24 @@ var Start = {
 		this.chart = new Chart();
 
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"start"	// callerClassName
+		);
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ENTER,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.startStage(); }).bind(this),	// keyUpHandler
+			"start"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			if(isTypingPracticeApp())
-				location.href = '../../web/client/menu_typing_practice.html';
-			else if(isTypingTestApp())
-				location.href = '../../web/client/menu_typing_test.html';
-			else
-				location.href = '../../web/client/menu_app.html';
-
-			sessionStorageManager.resetPlayingAppData();
-		});
+		screenTopUI.makeBackButton( function() { (function() { this.back(); }).bind(this) });
 		screenTopUI.makeFullScreenButton();
 
 
@@ -63,6 +69,17 @@ var Start = {
 		);
 	},
 
+	back: function() {
+		if(isTypingPracticeApp())
+			location.href = '../../web/client/menu_typing_practice.html';
+		else if(isTypingTestApp())
+			location.href = '../../web/client/menu_typing_test.html';
+		else
+			location.href = '../../web/client/menu_app.html';
+
+		sessionStorageManager.resetPlayingAppData();
+	},
+
 	loadHowToPlay: function(appID) {
 		this.dbConnectManager.requestHowToPlay(
 			sessionStorageManager.getPlayingAppID(),	// space_invaders app ID
diff --git a/src/game/typing/lib/keyboard.js b/src/game/typing/lib/keyboard.js
index 2fe91c4..2720304 100644
--- a/src/game/typing/lib/keyboard.js
+++ b/src/game/typing/lib/keyboard.js
@@ -2,6 +2,8 @@ function Keyboard(keyMapper, language, offsetY) {
 	this.keyMapper = keyMapper;
 	this.language = language;
 
+	this.keyHandlerMapper = {};
+
 	this.keyIndex = 0;
 	this.keyDataList = [];
 	this.keyList = [];
@@ -44,6 +46,20 @@ function Keyboard(keyMapper, language, offsetY) {
 	}
 }
 
+Keyboard.prototype.addCallback = function(keyCode, keyDownHandler, keyUpHandler, callerClassName) {
+	if(this.keyHandlerMapper[keyCode] != undefined) {
+		this.keyHandlerMapper[keyCode] = null;
+	}
+
+	this.keyHandlerMapper[keyCode] = {
+		"keyDownHandler": keyDownHandler,
+		"keyUpHandler": keyUpHandler,
+		"callerClassName": callerClassName
+	}
+
+	// console.log(this.keyHandlerMapper);
+}
+
 Keyboard.prototype.hideHighlight = function(text) {
 	var keyID = this.keyMapper.getKeyIDOfText(text);
 	this.allKeyHash[keyID].hideHighlight();
@@ -76,13 +92,27 @@ Keyboard.prototype.getKey = function(keyID) {
 Keyboard.prototype.keyDown = function(char) {
 	var keyCode = char.code;
 	this.setPressedSprite(keyCode);
+
+	if(this.keyHandlerMapper[char.keyCode] == undefined) {
+		// console.log(keyCode + " is down but not registered to KeyMapper");
+		return;
+	}
+
+	var keyMapper = this.keyHandlerMapper[char.keyCode];
+	var keyDownHandler = keyMapper["keyDownHandler"];
+	if(keyDownHandler == undefined)
+		return;
+
+	if(isDebugMode())
+		console.log(keyCode + " key is down (" + keyMapper["callerClassName"] + ")");
+	keyDownHandler();
 }
 
 Keyboard.prototype.setPressedSprite = function(keyCode) {
 	var keyID = this.keyMapper.getKeyIDOfText(keyCode);
 	var key = this.allKeyHash[keyID];
 	if(key === undefined) {
-		console.log(keyCode+ " is pressed but not registered to KeyMapper");
+		console.log(keyCode + " is pressed but not registered to KeyMapper");
 		return;
 	}
 
@@ -101,6 +131,20 @@ Keyboard.prototype.setPressedSprite = function(keyCode) {
 Keyboard.prototype.keyUp = function(char) {
 	var keyCode = char.code;
 	this.setNormalSprite(keyCode);
+
+	if(this.keyHandlerMapper[char.keyCode] == undefined) {
+		// console.log(keyCode + " is up but not registered to KeyMapper");
+		return;
+	}
+
+	var keyMapper = this.keyHandlerMapper[char.keyCode];
+	var keyUpHandler = keyMapper["keyUpHandler"];
+	if(keyUpHandler == undefined)
+		return;
+
+	if(isDebugMode())
+		console.log(keyCode + " key is up (" + keyMapper["callerClassName"] + ")");
+	keyUpHandler();
 }
 
 Keyboard.prototype.setNormalSprite = function(keyCode) {
diff --git a/src/game/typing/practice/game.js b/src/game/typing/practice/game.js
index 1bd6c97..e6f1cc5 100644
--- a/src/game/typing/practice/game.js
+++ b/src/game/typing/practice/game.js
@@ -17,10 +17,7 @@ var TypingPractice = {
 
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			sessionStorageManager.resetPlayingAppData();
-			location.href = '../../web/client/menu_typing_practice.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 
@@ -86,8 +83,14 @@ var TypingPractice = {
 			this.keyboard = new Keyboard(this.keyMapper, Keyboard.KOREAN, Keyboard.NO_OFFSET_POS_Y);
 		else
 			this.keyboard = new Keyboard(this.keyMapper, Keyboard.ENGLISH, Keyboard.NO_OFFSET_POS_Y);
+		this.keyboard.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"typing_practice"	// callerClassName
+		);
 
-		game.input.keyboard.processKeyPress = (function() {
+		game.input.keyboard.processKeyPress = (function(event) {
 			if(self.isOnStage === false)
 				return;
 
@@ -112,6 +115,12 @@ var TypingPractice = {
 		// this.countDown();
 	},
 
+
+	back: function() {
+		sessionStorageManager.resetPlayingAppData();
+		location.href = '../../web/client/menu_typing_practice.html';
+	},
+
 	startGame: function() {
 		this.isOnStage = true;
 		this.stageTimer.start();
@@ -353,7 +362,7 @@ var TypingPractice = {
 		return true;
 	},
 
-	checkTypingContents: function(evnet) {
+	checkTypingContents: function(event) {
 		var inputContent = event.key;
 		var typingContent = this.typingRandomContents[this.typingIndex];
 
diff --git a/src/game/typing/test/game.js b/src/game/typing/test/game.js
index 5448b73..6e6734d 100644
--- a/src/game/typing/test/game.js
+++ b/src/game/typing/test/game.js
@@ -13,12 +13,18 @@ var TypingTest = {
 
 		game.stage.backgroundColor = '#4d4d4d';
 
+		// keyboard shortcut
+		this.keyboardShortcut = new KeyboardShortcut();
+		this.keyboardShortcut.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"keyboard_test"	// callerClassName
+		);
+
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			sessionStorageManager.resetPlayingAppData();
-			location.href = '../../web/client/menu_typing_test.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 
@@ -144,6 +150,12 @@ var TypingTest = {
 	}
 	*/
 
+
+	back: function() {
+		sessionStorageManager.resetPlayingAppData();
+		location.href = '../../web/client/menu_typing_test.html';
+	},
+
 	startGame: function() {
 		this.averageTypingSpeedText.print(0);
 
@@ -311,7 +323,7 @@ var TypingTest = {
 		this.inputTextContent.canvasInput.value('');
 	},
 
-	checkTypingContents: function(evnet) {
+	checkTypingContents: function(event) {
 		if(event.keyCode == Phaser.Keyboard.ENTER) {
 			// console.log("### enter ###");
 			var inputContent = this.inputTextContent.canvasInput.value();
diff --git a/src/game/typing/whac_a_mole/game.js b/src/game/typing/whac_a_mole/game.js
index 48bec0b..480117b 100644
--- a/src/game/typing/whac_a_mole/game.js
+++ b/src/game/typing/whac_a_mole/game.js
@@ -17,10 +17,7 @@ var WhacAMole = {
 
 		// top ui
 		var screenTopUI = new ScreenTopUI();
-		screenTopUI.makeBackButton( function() {
-			sessionStorageManager.resetPlayingAppData();
-			location.href = '../../web/client/menu_app.html';
-		});
+		screenTopUI.makeBackButton( (function() { this.back(); }).bind(this) );
 		screenTopUI.makeFullScreenButton();
 
 
@@ -115,6 +112,12 @@ var WhacAMole = {
 			this.keyboard = new Keyboard(this.keyMapper, Keyboard.KOREAN, Keyboard.WHAC_A_MOLE_OFFSET_POS_Y);
 		else
 			this.keyboard = new Keyboard(this.keyMapper, Keyboard.ENGLISH, Keyboard.WHAC_A_MOLE_OFFSET_POS_Y);
+		this.keyboard.addCallback(
+			Phaser.KeyCode.ESC,	// keyCode
+			null,	// keyDownHandler
+			(function() { this.back(); }).bind(this),	// keyUpHandler
+			"whac a mole"	// callerClassName
+		);
 
 		game.input.keyboard.processKeyPress = (function() {
 			if(self.isOnStage === false)
@@ -138,6 +141,12 @@ var WhacAMole = {
 		// this.countDown();
 	},
 
+
+	back: function() {
+		sessionStorageManager.resetPlayingAppData();
+		location.href = '../../web/client/menu_app.html';
+	},
+
 	startGame: function() {
 		this.isOnStage = true;
 		this.stageTimer.start();
@@ -415,7 +424,7 @@ var WhacAMole = {
 		return true;
 	},
 
-	checkTypingContents: function(evnet) {
+	checkTypingContents: function(event) {
 		var inputContent = event.key;
 		var typingContent = this.typingRandomLetters[this.typingIndex];
 
diff --git a/src/web/client/login.html b/src/web/client/login.html
index 5942a90..0c4e31b 100644
--- a/src/web/client/login.html
+++ b/src/web/client/login.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/input_type_text.js"></script>
 		<script src="../../game/lib/button/round_rect_button.js"></script>
 		<script src="../../game/lib/button/back_button.js"></script>
diff --git a/src/web/client/menu_app.html b/src/web/client/menu_app.html
index e8163b0..22f0ddd 100644
--- a/src/web/client/menu_app.html
+++ b/src/web/client/menu_app.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/input_type_text.js"></script>
 		<script src="../../game/lib/button/round_rect_button.js"></script>
 		<script src="../../game/lib/button/back_button.js"></script>
diff --git a/src/web/client/menu_app_play_free.html b/src/web/client/menu_app_play_free.html
index e4d3b27..2116b5d 100644
--- a/src/web/client/menu_app_play_free.html
+++ b/src/web/client/menu_app_play_free.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/input_type_text.js"></script>
 		<script src="../../game/lib/button/round_rect_button.js"></script>
 		<script src="../../game/lib/button/back_button.js"></script>
diff --git a/src/web/client/menu_typing_test.html b/src/web/client/menu_typing_test.html
index cdbf9b5..6c60a27 100644
--- a/src/web/client/menu_typing_test.html
+++ b/src/web/client/menu_typing_test.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/input_type_text.js"></script>
 		<script src="../../game/lib/button/round_rect_button.js"></script>
 		<script src="../../game/lib/button/back_button.js"></script>
diff --git a/src/web/client/ranking.html b/src/web/client/ranking.html
index 15a78ff..bb2db9c 100644
--- a/src/web/client/ranking.html
+++ b/src/web/client/ranking.html
@@ -16,6 +16,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/history_record_manager.js"></script>
diff --git a/src/web/client/result.html b/src/web/client/result.html
index 60aa7b8..d5197fa 100644
--- a/src/web/client/result.html
+++ b/src/web/client/result.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/date_util.js"></script>
diff --git a/src/web/client/space_invaders.html b/src/web/client/space_invaders.html
index 4903ac9..a1f20f7 100644
--- a/src/web/client/space_invaders.html
+++ b/src/web/client/space_invaders.html
@@ -16,6 +16,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/history_record_manager.js"></script>
 		<script src="../../game/lib/input_type_text.js"></script>
diff --git a/src/web/client/start.html b/src/web/client/start.html
index 8ae1d9a..ae70850 100644
--- a/src/web/client/start.html
+++ b/src/web/client/start.html
@@ -14,6 +14,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/date_util.js"></script>
diff --git a/src/web/client/typing_practice.html b/src/web/client/typing_practice.html
index e0496eb..4a74b97 100644
--- a/src/web/client/typing_practice.html
+++ b/src/web/client/typing_practice.html
@@ -16,6 +16,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/history_record_manager.js"></script>
diff --git a/src/web/client/typing_test.html b/src/web/client/typing_test.html
index 8f54c87..6183088 100644
--- a/src/web/client/typing_test.html
+++ b/src/web/client/typing_test.html
@@ -16,6 +16,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<!-- <script src="../../game/lib/keyboard_shortcut.js"></script> -->
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/history_record_manager.js"></script>
diff --git a/src/web/client/whac_a_mole.html b/src/web/client/whac_a_mole.html
index b74611b..ccf0021 100644
--- a/src/web/client/whac_a_mole.html
+++ b/src/web/client/whac_a_mole.html
@@ -16,6 +16,7 @@
 		<script src="../../game/global/global_variables.js"></script>
 
 		<!-- library source files -->
+		<script src="../../game/lib/keyboard_shortcut.js"></script>
 		<script src="../../game/lib/string_util.js"></script>
 		<script src="../../game/lib/number_util.js"></script>
 		<script src="../../game/lib/history_record_manager.js"></script>