startActivity() causing crash in Android

So I just started learning to develop Android apps, and I have a programming background (Python mainly), so I somewhat know what I'm doing. I'm having a problem with using startActivity(). I've commented code to figure out exactly where the error gets thrown, and it happens right as startActivity() is encountered. The error I get is from the emulator and it is just a popup window that says, "Unfortunately, Test has stopped." (Test is my program name) after I click my button. My code is this

public class DisplayMessageActivity extends Activity {
     @Override
     public void onCreate(Bundle savedInstanceState){
         super.onCreate(savedInstanceState);
     }
 }
 
 public void sendMessage(View view) {
     Intent intent = new Intent(this, DisplayMessageActivity.class);
     EditText editText = (EditText) findViewById(R.id.textBox1);
     String message = editText.getText().toString();
     intent.putExtra(EXTRA_MESSAGE, message);
     startActivity(intent);
 }
 

Now I know that won't do anything yet, but why is it crashing?
My XML:

<?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="horizontal" >
 
 <EditText android:id="@+id/textBox1"
     android:layout_weight="1"
     android:layout_width="0dp"
     android:layout_height="wrap_content"
     android:hint="@string/textBox1Hint" />
 <Button 
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:text="@string/button1"
     android:onClick="sendMessage" />   
 
 </LinearLayout>
 

My manifest:

<?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.test.test"
 android:versionCode="1"
 android:versionName="1.0" >
 
 <uses-sdk android:minSdkVersion="15" />
 
 <application
     android:icon="@drawable/ic_launcher"
     android:label="@string/app_name" >
     <activity
         android:name=".TestActivity"
         android:label="@string/app_name" >
         <intent-filter>
             <action android:name="android.intent.action.MAIN" />
 
             <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
     </activity>
 
     <activity
         android:name=".DisplayMessageActivity" >
     </activity>
 
 </application>
 </manifest>
 

I saw that a lot of other people were having problems with this because they had not declared their activities in the manifest, but I think I have done so properly. Any help would be so greatly appreciated.

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