title: facebook session expires in android
body: <p>i am using facebook api in my android project </p>
  
  <pre><code>{"error":{"type":"OAuthException","message":"Error validating access token:
  Session has expired at unix time 1307350800.
  The current unix time is 1307352870."}}
  </code></pre>
  
  <p>My session expires....after a while....i want it as session never...expires</p>
  
  <p>expecting piece a piece code..so that session never endsup</p>
  
  <p>am using this for authorizing</p>
  
  <pre><code>    facebook.authorize(SignIn.this,
                      new DialogListener() {
  </code></pre>