diff --git a/Android/app/src/main/java/tw/edu/kuas/wifiautologin/libs/LoginHelper.java b/Android/app/src/main/java/tw/edu/kuas/wifiautologin/libs/LoginHelper.java
index 28a46cc..9f4354e 100644
--- a/Android/app/src/main/java/tw/edu/kuas/wifiautologin/libs/LoginHelper.java
+++ b/Android/app/src/main/java/tw/edu/kuas/wifiautologin/libs/LoginHelper.java
@@ -61,6 +61,7 @@ public static void login(final Context context, final UserModel model,
 
 			@Override
 			public void onFailure(Call call, IOException e) {
+				call.cancel();
 				loginFail(context, context.getString(R.string.login_timeout), callback);
 			}
 
@@ -113,11 +114,13 @@ private static void login(final Context context, final String location,
 
 			@Override
 			public void onFailure(Call call, IOException e) {
+				call.cancel();
 				loginFail(context, context.getString(R.string.login_timeout), callback);
 			}
 
 			@Override
 			public void onResponse(Call call, Response response) {
+				call.cancel();
 				try {
 					String _response = response.body().string();
 					if (_response.contains("login_online_detail.php")) {
@@ -164,6 +167,7 @@ public static void logout(final Context context, final boolean recheck,
 
 			@Override
 			public void onFailure(Call call, IOException e) {
+				call.cancel();
 				callback.onFail(context, context.getString(R.string.failed_to_logout));
 			}
 
@@ -210,11 +214,13 @@ private static void logout(final Context context, String location,
 
 			@Override
 			public void onFailure(Call call, IOException e) {
+				call.cancel();
 				callback.onFail(context, context.getString(R.string.failed_to_logout));
 			}
 
 			@Override
 			public void onResponse(Call call, Response response) {
+				call.cancel();
 				if (response.code() == 200) {
 					callback.onSuccess(context, context.getString(R.string.logout_successful));
 					NotificationHelper.cancelNotification(context, Constant.NOTIFICATION_LOGIN_ID);
@@ -274,12 +280,15 @@ private static void loginSuccess(Context context, String location,
 
 	private static void loginFail(Context context, String reason,
 	                              @NonNull GeneralCallback callback) {
-		NotificationHelper.cancelNotification(context, Constant.NOTIFICATION_LOGIN_ID);
-		callback.onFail(context, reason);
 		if (!(context instanceof MainActivity)) {
 			NotificationHelper.createNotification(context, reason, false, true,
 					Constant.NOTIFICATION_FAIL_ID);
 		}
+		NotificationHelper.cancelNotification(context, Constant.NOTIFICATION_LOGIN_ID);
+		NotificationHelper.cancelNotification(context, Constant.NOTIFICATION_FAIL_ID);
+		NotificationHelper.cancelNotification(context, Constant.NOTIFICATION_ALREADY_ID);
+
+		callback.onFail(context, reason);
 	}
 
 }
diff --git a/Android/build.gradle b/Android/build.gradle
index d06d2c2..b905bb1 100644
--- a/Android/build.gradle
+++ b/Android/build.gradle
@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.3'
+        classpath 'com.android.tools.build:gradle:2.3.0'
         classpath 'com.google.gms:google-services:3.0.0'
 
         // NOTE: Do not place your application dependencies here; they belong
diff --git a/Android/gradle/wrapper/gradle-wrapper.properties b/Android/gradle/wrapper/gradle-wrapper.properties
index c3ff205..a0124af 100644
--- a/Android/gradle/wrapper/gradle-wrapper.properties
+++ b/Android/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Feb 27 00:19:18 GMT+08:00 2017
+#Tue Mar 07 13:23:34 GMT+08:00 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip