title: The Admob interstitial doesn't work in my Android app
body: <p>I copied the code of the interstitial from here <a href="https://developers.google.com/mobile-ads-sdk/docs/admob/advanced" rel="nofollow">https://developers.google.com/mobile-ads-sdk/docs/admob/advanced</a> but it doesnt' work. When the app calls the method interstitial.isLoaded(), it crashes. This is the logcat:</p>
  
  <pre><code>04-06 14:40:09.320  29704-30638/? W/dalvikvm﹕ threadid=16: thread exiting with uncaught exception (group=0x4145e438)
  04-06 14:40:09.330  29704-30638/? E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-3225
      java.lang.IllegalStateException: isLoaded must be called on the main UI thread.
              at bkm.b(SourceFile:174)
              at xx.e(SourceFile:210)
              at yh.onTransact(SourceFile:66)
              at android.os.Binder.transact(Binder.java:326)
              at com.google.android.gms.internal.ac$a$a.isReady(Unknown Source)
              at com.google.android.gms.ads.InterstitialAd.isLoaded(Unknown Source)
              at com.MyApp.GameActivity.displayInterstitial(GameActivity.java:75)
              at com.MyApp.GameActivity$GameView.onDraw(GameActivity.java:300)
              at com.MyApp.GameActivity$GameLoop.run(GameActivity.java:524)
  04-06 14:40:09.330     441-4437/? W/ActivityManager﹕ Force finishing activity...
  </code></pre>
  
  <p>How is it possible? Can you please explain me step-by-step what I have to do to show this interstitial?
  Thank you in advance</p>