title: Show Interstitial Ad via AdMob in Ionic every 2 minutes
body: <p>I'm using AdMob plugin in Ionic and with this code I show an Interstital ad:</p>
  
  <pre><code> function initAd(){
       // it will display smart banner at top center, using the default options
       if(AdMob) AdMob.createBanner( {
           adId: admobid.banner,
           bannerId: admobid.banner,
           position: AdMob.AD_POSITION.BOTTOM_CENTER,
           autoShow: true,
           isTesting: false,
           success: function() {
               console.log('banner created');
           },
           error: function() {
               console.log('failed to create banner');
           }
       });
  
  
      window.AdMob.prepareInterstitial({
          adId:admobid.interstitial, autoShow:false
      });
      window.AdMob.showInterstitial();
  }
  </code></pre>
  
  <p>Is there a way to show intersitial ad every 2 minutes? Someone told me to add this: <code>setInterval(showInterstitial,1*60*1000)</code>, but I don't know where to add?</p>