diff --git a/src/main/java/istlab/KisoJikken/JTAConsole.java b/src/main/java/istlab/KisoJikken/JTAConsole.java
index 76265e1..2be62ce 100644
--- a/src/main/java/istlab/KisoJikken/JTAConsole.java
+++ b/src/main/java/istlab/KisoJikken/JTAConsole.java
@@ -344,7 +344,7 @@
             String json = gson.toJson(sjd);
             PostHTTP postHttp = new PostHTTP(json);
             try {
-                postHttp.execute();
+                JOptionPane.showMessageDialog(this, postHttp.execute());
             } catch (IOException e1) {
                 e1.printStackTrace();
             }
@@ -359,7 +359,7 @@
 }
 
 class SendJsonData {
-    public static String studentID = "(anonymous)";
+    public static String studentID = null;
     public String orig, buffer;
     public String markdown;
     public String mainsrc;
diff --git a/src/main/java/istlab/KisoJikken/PostHTTP.java b/src/main/java/istlab/KisoJikken/PostHTTP.java
index ad30314..46fa64e 100644
--- a/src/main/java/istlab/KisoJikken/PostHTTP.java
+++ b/src/main/java/istlab/KisoJikken/PostHTTP.java
@@ -48,6 +48,7 @@
         // 正常終了時はHttpStatusCode 200が返ってくる
         if (conn.getResponseCode() != 200) {
             // エラー処理
+            return "Error: "+conn.getResponseCode();
         }
 
         // HttpURLConnectionからInputStreamを取得し、読み出す