AdMob findViewById returns null
<p>I'm trying to configure AdMod in my first Android project. When I try to run the app, findViewByID always returns null.</p>

<p>Here's the code of my main activity:</p>

<pre><code>import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.view.Window;


   import android.view.WindowManager;

public abstract class MyAndroidApp extends Activity {
    AdView adView;
    public static final  String MY_PUBLISHER_ID = "***********";

 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    AdRequest adRequest = new AdRequest();
    adRequest.addTestDevice(AdRequest.TEST_EMULATOR);
    adView = new AdView(this, AdSize.BANNER, MY_PUBLISHER_ID);

    //R.id.main has value, I can see it in Eclipse
    RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main);


    if ( mainLayout == null )
        Log.d("Error","Layout is null");
    else
    mainLayout.addView(adView);

    adView.loadAd(adRequest);
</code></pre>

<p>The XML File (under res\layout) has the following:</p>

<pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MyApp"     
    android:id="@+id/main"&gt;

    &lt;TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/hello_world" /&gt;
&lt;/RelativeLayout&gt;
</code></pre>

<p>When I debug, I can see value for R.id.main. However, the value of mainLayout is still null.</p>

<p>Thanks in advance.</p>
