diff --git a/src/main/java/cn/reddragon/eportal/Authenticator.java b/src/main/java/cn/reddragon/eportal/Authenticator.java
index 2f5745a..41e9582 100644
--- a/src/main/java/cn/reddragon/eportal/Authenticator.java
+++ b/src/main/java/cn/reddragon/eportal/Authenticator.java
@@ -2,9 +2,12 @@
 
 import cn.reddragon.eportal.utils.HttpUtils;
 
+import java.awt.*;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.net.HttpURLConnection;
+import java.net.NoRouteToHostException;
+import java.net.SocketTimeoutException;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -77,7 +80,39 @@ public static boolean isOnline() {
                 online = false;
                 return false;
             }
-        } catch (Exception e) {
+        } catch (SocketTimeoutException e) {
+            if (SystemTray.isSupported()) {
+                SystemTray tray = SystemTray.getSystemTray();
+                Image image = Toolkit.getDefaultToolkit().createImage("icon.png");
+                TrayIcon icon = new TrayIcon(image, "Error");
+                icon.setImageAutoSize(true);
+                try {
+                    tray.add(icon);
+                } catch (AWTException e1) {
+                    throw new RuntimeException(e1);
+                }
+                icon.displayMessage("Error", "Connection timeout!", TrayIcon.MessageType.ERROR);
+                tray.remove(icon);
+                System.exit(0);
+            }
+            return false;
+        } catch (NoRouteToHostException e) {
+            if (SystemTray.isSupported()) {
+                SystemTray tray = SystemTray.getSystemTray();
+                Image image = Toolkit.getDefaultToolkit().createImage("icon.png");
+                TrayIcon icon = new TrayIcon(image, "Error");
+                icon.setImageAutoSize(true);
+                try {
+                    tray.add(icon);
+                } catch (AWTException e1) {
+                    throw new RuntimeException(e1);
+                }
+                icon.displayMessage("Error", "No Internet connection!", TrayIcon.MessageType.ERROR);
+                tray.remove(icon);
+                System.exit(0);
+            }
+            return false;
+        } catch (IOException e) {
             online = false;
             return false;
         }
diff --git a/src/main/java/cn/reddragon/eportal/Config.java b/src/main/java/cn/reddragon/eportal/Config.java
index ea02089..3ad4f78 100644
--- a/src/main/java/cn/reddragon/eportal/Config.java
+++ b/src/main/java/cn/reddragon/eportal/Config.java
@@ -1,6 +1,9 @@
 package cn.reddragon.eportal;
 
-import java.io.*;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 
@@ -47,7 +50,6 @@ public static String[] read() throws IOException {
             }
             String password = new String(b1);
             stream.close();
-            System.out.println(username + " " + password);
             return new String[]{username, password};
         } catch (Exception e) {
             e.printStackTrace();
diff --git a/src/main/java/cn/reddragon/eportal/HelloApplication.java b/src/main/java/cn/reddragon/eportal/HelloApplication.java
index 7f1643a..aea1bc3 100644
--- a/src/main/java/cn/reddragon/eportal/HelloApplication.java
+++ b/src/main/java/cn/reddragon/eportal/HelloApplication.java
@@ -12,14 +12,19 @@
 import javafx.scene.control.TextField;
 import javafx.stage.Stage;
 
-import java.io.IOException;
 import java.awt.*;
+import java.io.IOException;
 
 public class HelloApplication extends Application {
     private static Label statusLabel;
     private static Button button;
     public static final Thread askThread = new Thread(() -> {
         while (true) {
+            try {
+                Thread.sleep(2500L);
+            } catch (InterruptedException e) {
+                //throw new RuntimeException(e);
+            }
             Authenticator.isOnline();
             Platform.runLater(() -> {
                 statusLabel.setText("Current status:" + (Authenticator.online ? "Online" : "Offline"));
@@ -29,11 +34,6 @@ public class HelloApplication extends Application {
                     button.setText("Login");
                 }
             });
-            try {
-                Thread.sleep(2500L);
-            } catch (InterruptedException e) {
-                //throw new RuntimeException(e);
-            }
         }
     });
 
@@ -84,7 +84,6 @@ public static void main(String[] args) {
             e.printStackTrace();
             System.exit(0);
         } catch (IOException ignored) {
-
         }
         launch();
         System.exit(0);
diff --git a/src/main/java/cn/reddragon/eportal/HelloController.java b/src/main/java/cn/reddragon/eportal/HelloController.java
index ed51f3c..6e49584 100644
--- a/src/main/java/cn/reddragon/eportal/HelloController.java
+++ b/src/main/java/cn/reddragon/eportal/HelloController.java
@@ -3,7 +3,8 @@
 import cn.reddragon.eportal.utils.HttpUtils;
 import cn.reddragon.eportal.utils.IOUtils;
 import cn.reddragon.eportal.utils.URIEncoder;
-import com.google.gson.*;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
 import javafx.fxml.FXML;
 import javafx.scene.control.Button;
 import javafx.scene.control.ChoiceBox;
@@ -29,7 +30,7 @@ public class HelloController {
 
     @FXML
     protected void onLoginButtonClick() {
-        if (Authenticator.isOnline()) {
+        if (Authenticator.online) {
             if (button.getText().equals("Login")) {
                 resultText.setText("Already logged in!");
                 button.setText("Logout");