diff --git a/hwb1/src/hwb1/MyApplet.java b/hwb1/src/hwb1/MyApplet.java
index 06696e3..02c5513 100644
--- a/hwb1/src/hwb1/MyApplet.java
+++ b/hwb1/src/hwb1/MyApplet.java
@@ -51,40 +51,44 @@ public class MyApplet extends Applet {
     public void process(APDU apdu) {
         short length;
         byte[] buffer = apdu.getBuffer();
+        
+        if (buffer[ISO7816.OFFSET_CLA] != 0x80) {
+            ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
+        } else {
+            byte instruction = buffer[ISO7816.OFFSET_INS];
 
-        byte instruction = buffer[ISO7816.OFFSET_INS];
+            switch (instruction) {
+                case 0x00:
+                case 0x04:
+                    byte[] response;
+                    length = apdu.setOutgoing();
 
-        switch (instruction) {
-            case 0x00:
-            case 0x04:
-                byte[] response;
-                length = apdu.setOutgoing();
+                    if (instruction == 0x00) {
+                        response = AuthorName;
+                    } else {
+                        response = storage;
+                    }
 
-                if (instruction == 0x00) {
-                    response = AuthorName;
-                } else {
-                    response = storage;
-                }
+                    if (length > response.length) {
+                        length = (short) response.length;
+                    }
 
-                if (length > response.length) {
-                    length = (short) response.length;
-                }
+                    apdu.setOutgoingLength(length);
+                    apdu.sendBytesLong(response, (short) 0, length);
+                    break;
+                case 0x02:
+                    length = apdu.setIncomingAndReceive();
 
-                apdu.setOutgoingLength(length);
-                apdu.sendBytesLong(response, (short) 0, length);
-                break;
-            case 0x02:
-                length = apdu.setIncomingAndReceive();
-
-                if (length > 20) {
-                    // ToDo: Handle too much data.
-                } else {
-                    Util.arrayCopy(buffer, ISO7816.OFFSET_CDATA, storage, (short) 0, length);
-                }
-                break;
-            default:
-                ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
-                break;
+                    if (length > 20) {
+                        // ToDo: Handle too much data.
+                    } else {
+                        Util.arrayCopy(buffer, ISO7816.OFFSET_CDATA, storage, (short) 0, length);
+                    }
+                    break;
+                default:
+                    ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
+                    break;
+            }
         }
     }
 }