title: After click AdMob ads, I cannot return to my Android app by back button
body: <p>I add AdMob in my application using the following code.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
       &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent"
       android:orientation="vertical" &gt;
  &lt;com.google.ads.AdView 
      android:id="@+id/adview"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      ads:adSize="SMART_BANNER" 
      ads:adUnitId="ca-app-pub-*************************"
      ads:loadAdOnCreate="true"
      ads:testDevices="********************"
      /&gt;
   &lt;TabHost
      android:id="@android:id/tabhost"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" &gt;
  
      &lt;LinearLayout
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:orientation="vertical"
          &gt;
  
          &lt;TabWidget
              android:id="@android:id/tabs"
              android:textSize="12sp"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content" /&gt;
  
          &lt;FrameLayout
              android:id="@android:id/tabcontent"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent" &gt;
          &lt;/FrameLayout&gt;
      &lt;/LinearLayout&gt;
   &lt;/TabHost&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>The ad is displayed on my phone. However, it does not return to my app when I touch "Back" button. Instead, it returns to my phone web pages previously viewed.
  Any suggestions are welcome.</p>