var iframe = document.querySelector('#third-party-tracking-sandbox-iframe');
      var url = "https://www.wf-box.net/sandboxed_ad_vendor_iframe.html";
      iframe.addEventListener('load', function() {
        iframe.contentWindow.postMessage({
          isAdTracking: true,
          trackingType: 'reddit',
          eventName: 'PageVisit'
        }, 'https://www.wf-box.net');
      });
      iframe.setAttribute('src', url + window.location.search);