title: Can not open session for facebook
body: <p>I had make FBLogin demo using <a href="https://developers.facebook.com/docs/getting-started/facebook-sdk-for-android/3.0/" rel="nofollow">this tutotial</a></p>
  
  <p>Code is here //MainActivity.java</p>
  
  <pre><code>public class MainActivity extends Activity {
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
  
      // start Facebook Login
      Session.openActiveSession(this, true, new Session.StatusCallback() {
  
          // callback when session changes state
          @Override
          public void call(Session session, SessionState state,
                  Exception exception) {
  
              Log.v("log_tag", "Token=" + session.getAccessToken());
              Log.v("log_tag", "Token=" + session.isOpened());
  
              if (session.isOpened()) {
  
                  // make request to the /me API
                  Request.executeMeRequestAsync(session,
                          new Request.GraphUserCallback() {
  
                              // callback after Graph API response with user
                              // object
                              @Override
                              public void onCompleted(GraphUser user,
                                      Response response) {
                                  if (user != null) {
                                      TextView welcome = (TextView) findViewById(R.id.welcome);
                                      welcome.setText("Hello "
                                              + user.getName() + "!");
                                  }
                              }
                          });
              }
          }
      });
  
  }
  
  @Override
  public void onActivityResult(int requestCode, int resultCode, Intent data) {
      super.onActivityResult(requestCode, resultCode, data);
      Session.getActiveSession().onActivityResult(this, requestCode,
              resultCode, data);
  }
  }
  </code></pre>
  
  <p>//AndroidManifest.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.fbdemo"
  android:versionCode="1"
  android:versionName="1.0" &gt;
  
  &lt;uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="8" /&gt;
  
  &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
  
  &lt;application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
      &lt;activity
          android:name="com.example.fbdemo.MainActivity"
          android:label="@string/app_name" &gt;
           &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
  
      &lt;activity android:name="com.facebook.LoginActivity" /&gt;
  
      &lt;meta-data
          android:name="com.facebook.sdk.ApplicationId"
          android:value="@string/app_id" /&gt;
  &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>
  
  <p>output in <code>log_cat</code> is like this</p>
  
  <pre><code>02-14 19:08:25.251: V/log_tag(1558): Token=
  02-14 19:08:25.251: V/log_tag(1558): Token=false
  02-14 19:08:38.834: V/log_tag(1558): Token=
  02-14 19:08:38.834: V/log_tag(1558): Token=false
  </code></pre>
  
  <p>please tell me where is the problem?</p>