diff --git a/src/main/java/info/istlab/IoTP/MqttWindow.java b/src/main/java/info/istlab/IoTP/MqttWindow.java
index 994272c..f87a72a 100644
--- a/src/main/java/info/istlab/IoTP/MqttWindow.java
+++ b/src/main/java/info/istlab/IoTP/MqttWindow.java
@@ -124,6 +124,7 @@
         // jta.requestFocus();
         appendToJTA("まだ接続していません。Topicを設定してConnectをおしてください。\n");
     }
+
     @Override
     public void run() {
         subscriber = new MqttSubscriber(brokerjtf.getText(), brokerportjtf.getText(), topicjtf.getText(), this);
@@ -141,10 +142,9 @@
         appendToJTA("Connected.\n");
         jta.setBackground(Color.white);
         topicjtf.setEditable(false);
-        connectB.setText("Disconnect");    
+        connectB.setText("Disconnect");
     }
 
-
     private void connect(ActionEvent e) {
         if (e.getActionCommand().equals("Connect")) {
             if (thread != null) {
@@ -242,18 +242,18 @@
     // }
 
     private void closeWin() {
-        if (subscriber == null)
-            return;
-        try {
-            subscriber.unsubscribe();
-        } catch (MqttException | InterruptedException e1) {
-            e1.printStackTrace();
-        } finally {
-            subscriber = null;
-            appendToJTA("Disconnected.\n");
-            jta.setBackground(Color.gray);
-            MqttWindow.theMqttWindow = null;
+        if (subscriber != null) {
+            try {
+                subscriber.unsubscribe();
+            } catch (MqttException | InterruptedException e1) {
+                e1.printStackTrace();
+            } finally {
+                subscriber = null;
+                appendToJTA("Disconnected.\n");
+                jta.setBackground(Color.gray);
+            }
         }
+        MqttWindow.theMqttWindow = null;
         connectB.setText("Connect");
         if (Launcher.theapp == null || !Launcher.theapp.isVisible())
             System.exit(0);