title: Facebook banner ad in unity align to the bottom
body: <p>cannot align the facebook audience banner ad to the bottom of my screen. i tried to nested it in a canves align the object to the bottom but when ever call the show method it start count from the top of the screen.
  i tried to make it static like this </p>
  
  <pre><code>adView.Show(135);
  </code></pre>
  
  <p>it works fine on my phone but when i tried on bigger screen it's appear on the middle.
  i tried also to change the static value with <code>adView.Show(canves.rect.height - 50);</code>
  but the result is samiler  <code>adView.Show(AdUtility.height());</code>
  but it's appear out of the screen.i use unity 5.2.2f1 and facebook audience sdk 4.7.0</p>