diff --git a/src/web/admin/admin_register_list.html b/src/web/admin/admin_register_list.html
index 7dac0de..6f9dc59 100644
--- a/src/web/admin/admin_register_list.html
+++ b/src/web/admin/admin_register_list.html
@@ -39,7 +39,7 @@
 					updateMaestroList(jsonData["maestroList"]);
 				},
 
-				(errorMessage) => {
+				(errorMessage, errorCode) => {
 					if($("#error_message").length) {
 						$("#error_message").text(errorMessage);
 					}
@@ -104,7 +104,7 @@
 					$("#error_message").text("마에스트로 계정이 정상적으로 등록되었습니다.");
 				},
 
-				(errorMessage) => {
+				(errorMessage, errorCode) => {
 					if($("#error_message").length) {
 						$("#error_message").text(errorMessage);
 					}
diff --git a/src/web/admin/admin_section.html b/src/web/admin/admin_section.html
deleted file mode 100644
index 36ae8a9..0000000
--- a/src/web/admin/admin_section.html
+++ /dev/null
@@ -1,135 +0,0 @@
-<style>
-.player_free {
-	/*background-color: #ff0000;*/
-	padding: 20px;
-}
-
-.maestro_free {
-	/*background-color: #0000ff;*/
-	padding: 20px;
-}
-</style>
-
-
-
-<script>
-
-function loadMaestroTestAccountInfo() {
-	let xhr = new XMLHttpRequest(); //new로 생성.
-	xhr.open('POST', './../server/maestro/maestro_test_account.php', true);
-	xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
-	xhr.send();
-	xhr.onload = function() {
-		if(xhr.readyState === 4 && xhr.status === 200) {
-			// console.log(xhr.responseText);
-			// console.log(xhr.responseText.length);
-			if(xhr.responseText.length === 0 || xhr.responseText === null) {
-				console.log("no data from server");
-				return;
-			}
-
-			let replyJSON = JSON.parse(xhr.responseText);
-			// console.log(replyJSON);
-
-			if(replyJSON === null) {
-				console.log("no data from server");
-				return;
-			}
-
-			if(replyJSON["ERROR"] !== undefined || replyJSON["RESULT"] === undefined) {
-				console.log(replyJSON["ERROR"]);
-				return;
-			}
-
-			if(replyJSON["RESULT"] === "fail") {
-				console.log(replyJSON["RESULT"]);
-				return;
-			}
-
-			let maestroID = replyJSON["maestroID"];
-			let playerID = replyJSON["playerID"];
-			let playerName = replyJSON["playerName"];
-
-			console.log("maestroID : " + maestroID);
-			console.log("playerID : " + playerID);
-			console.log("playerName : " + playerName);
-
-			sessionStorage.setItem("maestroID", maestroID);
-			sessionStorage.setItem("playerID", playerID);
-			sessionStorage.setItem("playerName", playerName);
-		}
-	}
-}
-
-function playFree() {
-	loadMaestroTestAccountInfo();
-	window.open("./../client/menu_app.html", "_blank");
-}
-
-function experienceMaestro() {
-	loadMaestroTestAccountInfo();
-	location.href = "./../maestro/main_menu.html";
-}
-
-</script>
-
-
-
-<div class="container">
-	<div class="player_free">
-		<div class="col alignCenter">
-			<a id="player_free_play" class="btn btn-rouge width400" onClick="playFree()" >학생 연습 앱<br/>무료 체험</a>
-		</div>
-
-		<ul id="free_app_list">
-			<li>
-				마우스 클릭 연습
-			</li>
-			<li>
-				마우스 더블 클릭 연습
-			</li>
-			<li>
-				한글 키보드 연습
-			</li>
-		</ul>
-
-	</div>
-
-	<div class="maestro_free">
-		<div class="col alignCenter">
-			<a id="maestro_free_menu" class="btn btn-sea width400" onClick="experienceMaestro()" >마에스트로<br/>관리자 메뉴 체험</a>
-		</div>
-
-		<ul id="maestro_preview">
-			<li>
-				플레이어 관리
-			</li>
-			<li>
-				과목 관리
-			</li>
-			<li>
-				랭킹
-			</li>
-			<li>
-				기록
-			</li>
-		</ul>
-
-		<div class="col alignCenter">
-			<a href="./../maestro/register.html" id="maestro_register" class="btn btn-sea width400">마에스트로<br/>가입</a>
-		</div>
-
-		<ul id="register_tip">
-			<li>
-				학생 20명 (1만원 / 1년)
-			</li>
-			<li>
-				학생 50명 (2만원 / 1년)
-			</li>
-			<li>
-				학생 100명 (3만원 / 1년)
-			</li>
-		</ul>
-
-	</div>
-</div>
diff --git a/src/web/admin/login.html b/src/web/admin/login.html
index 1a006d7..76db4a4 100644
--- a/src/web/admin/login.html
+++ b/src/web/admin/login.html
@@ -33,7 +33,7 @@
 					location.href = 'admin_register_list.html';
 				},
 
-				(errorMessage) => {
+				(errorMessage, errorCode) => {
 					if($("#error_message").length) {
 						$("#error_message").text(errorMessage);
 					}
diff --git a/src/web/css/admin.css b/src/web/css/admin.css
index c5111da..888ed0f 100644
--- a/src/web/css/admin.css
+++ b/src/web/css/admin.css
@@ -2,17 +2,6 @@
 
 <style type="text/css">
 
-.login {
-	background-color: #ff0000;
-	padding: 20px;
-}
-
-.register {
-	background-color: #0000ff;
-	padding: 20px;
-}
-
-
 .hide {
 	display: none;
 }
diff --git a/src/web/css/maestro_main.css b/src/web/css/maestro_main.css
index ec00711..9e53be4 100644
--- a/src/web/css/maestro_main.css
+++ b/src/web/css/maestro_main.css
@@ -2,17 +2,6 @@
 
 <style type="text/css">
 
-.login {
-	background-color: #ff0000;
-	padding: 20px;
-}
-
-.register {
-	background-color: #0000ff;
-	padding: 20px;
-}
-
-
 .hide {
 	display: none;
 }
diff --git a/src/web/js/player_list_manager.js b/src/web/js/player_list_manager.js
index da30e17..05c9c21 100644
--- a/src/web/js/player_list_manager.js
+++ b/src/web/js/player_list_manager.js
@@ -31,7 +31,7 @@
 				self.listNavigator.updateNavigator(self.activePageNo, self.lastPageNo);
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -99,7 +99,7 @@
 				self.list.updatePlayerList(jsonData["playerList"]);
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -168,7 +168,7 @@
 				self.listNavigator.updateNavigator(self.activePageNo, self.lastPageNo);
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -240,7 +240,7 @@
 				self.updateSearchPlayerListPage(playerName, 1);
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -308,7 +308,7 @@
 				self.listNavigator.updateNavigator(self.activePageNo, self.lastPageNo);
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -422,7 +422,7 @@
 				}
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
@@ -499,7 +499,7 @@
 				}
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
diff --git a/src/web/maestro/maestro_test_account_app_menu.html b/src/web/maestro/maestro_test_account_app_menu.html
index df2858f..d5e2491 100644
--- a/src/web/maestro/maestro_test_account_app_menu.html
+++ b/src/web/maestro/maestro_test_account_app_menu.html
@@ -37,7 +37,7 @@
 					location.href = "./../client/menu_app.html";
 				},
 
-				(errorMessage) => {
+				(errorMessage, errorCode) => {
 					if($("#error_message").length) {
 						$("#error_message").text(errorMessage);
 					}
diff --git a/src/web/main/free_player_app_menu.html b/src/web/main/free_player_app_menu.html
index df2858f..d5e2491 100644
--- a/src/web/main/free_player_app_menu.html
+++ b/src/web/main/free_player_app_menu.html
@@ -37,7 +37,7 @@
 					location.href = "./../client/menu_app.html";
 				},
 
-				(errorMessage) => {
+				(errorMessage, errorCode) => {
 					if($("#error_message").length) {
 						$("#error_message").text(errorMessage);
 					}
diff --git a/src/web/module/home_section.html b/src/web/module/home_section.html
index e3557be..ded7f0a 100644
--- a/src/web/module/home_section.html
+++ b/src/web/module/home_section.html
@@ -33,7 +33,7 @@ function loadMaestroTestAccountInfo() {
 			sessionStorage.setItem("playerName", playerName);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
diff --git a/src/web/module/maestro_header.html b/src/web/module/maestro_header.html
index 574fa5f..84e5ccb 100644
--- a/src/web/module/maestro_header.html
+++ b/src/web/module/maestro_header.html
@@ -39,7 +39,7 @@ function loadMaestroTestAccountInfo() {
 			sessionStorage.setItem("playerName", playerName);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
@@ -64,7 +64,7 @@ function deleteMaestroAllRecords() {
 				alert("마에스트로 전용 계정의 모든 플레이 기록이 지워졌습니다.");
 			},
 
-			(errorMessage) => {
+			(errorMessage, errorCode) => {
 				if($("#error_message").length) {
 					$("#error_message").text(errorMessage);
 				}
diff --git a/src/web/module/maestro_section_add_player.html b/src/web/module/maestro_section_add_player.html
index 6189c68..433da51 100644
--- a/src/web/module/maestro_section_add_player.html
+++ b/src/web/module/maestro_section_add_player.html
@@ -14,11 +14,13 @@ function addPlayer() {
 	let enterCode = $("#add_player_enter_code").val();
 
 	if(playerName.length === 0) {
-		$("#add_player_notice").val("학생 이름을 입력하세요.");
+		// $("#add_player_notice").val("학생 이름을 입력하세요.");
+		$("#error_message").text("학생 이름을 입력하세요.");
 		$("#add_player_name").focus();
 		return;
 	} else if(enterCode.length === 0) {
-		$("#add_player_notice").val("엔터 코드를 입력하세요.");
+		// $("#add_player_notice").val("엔터 코드를 입력하세요.");
+		$("#error_message").text("입장 번호를 입력하세요.");
 		$("#add_player_enter_code").focus();
 		return;
 	}
@@ -31,7 +33,7 @@ function addPlayer() {
 			addPlayerListManager.updateAddPlayerListPage(1);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
@@ -44,6 +46,14 @@ function addPlayer() {
 
 
 
+<div>
+	<span id="error_message">
+학생 이름 : (한글) 10글자, (영문) 20글자까지 입력 가능<br/>
+입장 코드 : 숫자 1~6자리 수
+	</span>
+</div>
+
+
 <span id="add_player">
 	<h2>추가</h2>
 
@@ -51,16 +61,10 @@ function addPlayer() {
 
 	<div>
 		학생 이름 <input type="text" name="name" id="add_player_name"><br/>
-		입장 코드 <input type="text" name="entercode" id="add_player_enter_code">
+		입장 번호 <input type="text" name="entercode" id="add_player_enter_code">
 		<input type='button' value="추가"" onClick="addPlayer()" >
 	</div>
 
-	<textarea id="add_player_notice">
-학생 이름 : (한글) 10글자, (영문) 20글자까지 입력 가능
-입장 코드 : 숫자 1~6자리 수
-	</textarea>
-
-
 	<!--
 	<h3>단체 추가</h3>
 
diff --git a/src/web/module/maestro_section_login.html b/src/web/module/maestro_section_login.html
index df6bbe5..97c8c65 100644
--- a/src/web/module/maestro_section_login.html
+++ b/src/web/module/maestro_section_login.html
@@ -1,16 +1,4 @@
-<style>
-.login {
-	background-color: #ff0000;
-	padding: 20px;
-}
-
-.register {
-	background-color: #0000ff;
-	padding: 20px;
-}
-</style>
-
-<script>
+<script>
 
 function login() {
 	let name = $("#maestro_name").val();
diff --git a/src/web/module/maestro_section_mouse_app.html b/src/web/module/maestro_section_mouse_app.html
index 053a0d1..491f55f 100644
--- a/src/web/module/maestro_section_mouse_app.html
+++ b/src/web/module/maestro_section_mouse_app.html
@@ -16,7 +16,7 @@ function loadMouseApp() {
 			activateMouseApp(jsonData["activatedAppList"]);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
@@ -67,7 +67,7 @@ function activateApp(appID) {
 			// addPlayerListManager.updateAddPlayerListPage(1);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
@@ -85,7 +85,7 @@ function deactivateApp(appID) {
 			// addPlayerListManager.updateAddPlayerListPage(1);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
 			}
diff --git a/src/web/module/maestro_section_register.html b/src/web/module/maestro_section_register.html
index be46f0c..63c0db4 100644
--- a/src/web/module/maestro_section_register.html
+++ b/src/web/module/maestro_section_register.html
@@ -53,9 +53,10 @@ function check_id() {
 
 		(jsonData) => {
 			isAvailableID = true;
+			$("#error_message").text(maestro_name + " : 생성 가능한 마에스트로 계정 이름입니다.");
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			isAvailableID = false;
 
 			if($("#error_message").length) {
@@ -72,21 +73,21 @@ function check_id() {
 
 function check_data() {
 	if(!isAvailableID) {
-		$("#error_message").val("아이디 중복 확인을 해 주세요.");
+		$("#error_message").text("아이디 중복 확인을 해 주세요.");
 		$("#check_id").focus();
 		return;
 	}
 
 	password = $("#password").val();
 	if(password.length === 0) {
-		$("#error_message").val("패스워드를 입력해 주세요.");
+		$("#error_message").text("패스워드를 입력해 주세요.");
 		$("#password").focus();
 		return;
 	}
 
 	email = $("#email").val();
 	if(email.length === 0) {
-		$("#error_message").val("이메일을 입력해 주세요.");
+		$("#error_message").text("이메일을 입력해 주세요.");
 		$("#email").focus();
 		return;
 	}
@@ -98,7 +99,7 @@ function check_data() {
 
 	let isCheckAcceptClauses = $("#check_accept_clauses").is(":checked");
 	if(!isCheckAcceptClauses) {
-		$("#error_message").val("약관을 읽고, 동의 체크 버튼을 눌러 주세요.");
+		$("#error_message").text("약관을 읽고, 동의 체크 버튼을 눌러 주세요.");
 		$("#check_accept_clauses").focus();
 		return;
 	}
@@ -131,7 +132,7 @@ function register_account() {
 			isAvailableID = true;
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			isAvailableID = false;
 
 			if($("#error_message").length) {
@@ -160,6 +161,12 @@ function register_account() {
 	</div>
 
 
+	<div>
+		<span id="error_message">
+		</span>
+	</div>
+
+
 	<div id="input_data">
 
 		(필수) 마에스트로 아이디 : <input type="text" id="maestro_name" value="test" >
@@ -185,8 +192,6 @@ function register_account() {
 		<br/>
 
 		<br/>
-		<textarea id="error_message">
-		</textarea>
 
 		<div class="col alignCenter">
 			<a id="agreement_clauses" class="btn btn-orange">전체 약관 읽기</a>
diff --git a/src/web/module/maestro_section_typing_app.html b/src/web/module/maestro_section_typing_app.html
index 28db516..7292923 100644
--- a/src/web/module/maestro_section_typing_app.html
+++ b/src/web/module/maestro_section_typing_app.html
@@ -16,7 +16,7 @@ function loadTypingApp() {
 			activateTypingApp(jsonData["activatedAppList"]);
 		},
 
-		(errorMessage) => {
+		(errorMessage, errorCode) => {
 			console.log(errorMessage);
 			if($("#error_message").length) {
 				$("#error_message").text(errorMessage);
diff --git a/src/web/server/maestro/check_id.php b/src/web/server/maestro/check_id.php
index a4ffc95..f4eca21 100644
--- a/src/web/server/maestro/check_id.php
+++ b/src/web/server/maestro/check_id.php
@@ -9,6 +9,7 @@ $maestro_name = $_POST["maestro_name"];
 
 $maestro_id = get_maestro_id($maestro_name);
 if($maestro_id !== null) {
+	set_error_code("registered_name");
 	set_error_message($maestro_name." : 이미 등록된 마에스트로 계정입니다.");
 	send_result_fail();
 	exit;