DFP bg takeover

gistfile1.js

var bgColor = '#163596',
    bgImg = 'http://i.imgur.com/7MDjqNU.jpg';
      
var space = window.parent.document.body,
  ad = space.querySelectorAll('#AD'),
  adClickURL = '%%CLICK_URL_UNESC%%';

space.style.backgroundColor = bgColor;
space.style.backgroundImage = 'url(%%VIEW_URL_UNESC%%' + bgImg + '?v=%%CACHEBUSTER%%)';
space.style.backgroundPosition = 'top center';
space.style.backgroundRepeat = 'no-repeat';
space.className = 'dfp-ad';