replace click url in ad iframe

click_url_replace.js

function receiveMessage(e) {
  var clickUrl;
  if (typeof e.data === 'string' && e.data.indexOf('clickUrl') > -1) {
    clickUrl = e.data.split('/')[1];
    var links = document.getElementsByTagName('a');
    [].forEach.call(links, function(link) {
      link.href = link.href.replace('%%CLICK_URL_UNESC%%', clickUrl);
    });
  }
}

window.addEventListener("message", receiveMessage, '*');