DFP Async Example - The only difference with the async tag is you must add "position absolute" in the DIV layer. - Click here to see only the example + code.
<script type='text/javascript'>
var googletag = googletag || {};
googletag.cmd = googletag.cmd || [];
(function() {
var gads = document.createElement('script');
gads.async = true;
gads.type = 'text/javascript';
var useSSL = 'https:' == document.location.protocol;
gads.src = (useSSL ? 'https:' : 'http:') +
'//www.googletagservices.com/tag/js/gpt.js';
var node = document.getElementsByTagName('script')[0];
node.parentNode.insertBefore(gads, node);
})();
</script>
<script type='text/javascript'>
var g_frame="/1055656/exp-smart";
googletag.cmd.push(function() {
googletag.defineSlot('/1055656/exp-smart', [728, 500], 'div-gpt-ad-1416304331853-0').addService(googletag.pubads());
googletag.pubads().enableSingleRequest();
googletag.enableServices();
});
</script>
<div id='div-gpt-ad-1416304331853-0' style='width:728px; height:90px;position:absolute'>
<script type='text/javascript'>
googletag.cmd.push(function() { googletag.display('div-gpt-ad-1416304331853-0'); });
</script>
</div>