title: Spinner on an ActionBar issue on a Dialog Activity
body: <p>Hi I have an activity that shows a dialog form an standard layout.</p>
  
  <p>android:theme="@android:style/Theme.Holo.Light.Dialog"/></p>
  
  <p>I was trying to add a simple spinner to the actionbar but I am having issues and error in the line  getActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_LIST).</p>
  
  <p>When I change my theme to a common activity it works perfect.</p>
  
  <p>This are the errors showed by the logcat:</p>
  
  <pre><code>3114-3114/org.PeteProto E/AndroidRuntime: FATAL EXCEPTION: main
          java.lang.RuntimeException: Unable to start activity ComponentInfo{org.PeteProto/org.PeteProto.Detail}: java.lang.NullPointerException
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
          at android.app.ActivityThread.access$600(ActivityThread.java:141)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
          at android.os.Handler.dispatchMessage(Handler.java:99)
          at android.os.Looper.loop(Looper.java:137)
          at android.app.ActivityThread.main(ActivityThread.java:5039)
          at java.lang.reflect.Method.invokeNative(Native Method)
          at java.lang.reflect.Method.invoke(Method.java:511)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
          at dalvik.system.NativeStart.main(Native Method)
          Caused by: java.lang.NullPointerException
          at org.PeteProto.Detail.onCreate(Detail.java:30)
          at android.app.Activity.performCreate(Activity.java:5104)
          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
          ... 11 more 
  </code></pre>