title: ChartBoost ad is not displaying in my view
body: <p>I am developing iPhone application. In that I want to use chartboost. I am new to this concept, so I used the code given in that website, but still it's not working. I used the above coding in appdelegate.m file. And added SystemConfiguration.framework and QuartzCore.framework. Is there anything else I have to do?</p>
  
  <pre><code>#import "Chartboost.h"
  - (void)applicationDidBecomeActive:(UIApplication *)application {
  // Configure ChartBoost
  ChartBoost *cb = [ChartBoost sharedChartBoost]; cb.appId = @"APP_ID";
  cb.appSignature = @"APP_SIGNATURE";
  // Notify the beginning of a user session
  [cb startSession];
  // Show an interstitial
  [cb showInterstitial]; }
  </code></pre>