Setup hangout button in my website

I have strange problem. I'm trying to integrate hangout button in my website to enable user to open the lecture directly from the website and I used the sample code in Google Hangout API Documentation http://ift.tt/1DW9wKP button it didn't work, so what is the problem ?

<script src="http://ift.tt/1bMh26W" async defer>   </script>
<div id="placeholder-div3"></div>
<script>
 gapi.hangout.render('placeholder-div3', {
'render': 'createhangout',
'hangout_type': 'onair',
'initial_apps': [{'app_id' : '184219133185', 'start_data' : 'dQw4w9WgXcQ', 'app_type' : 'ROOM_APP' }],
'widget_size': 175
 });
</script>