We can not fetch videos from this type of page.
Your URL was: http://download-video.js';document.body.appendChild(document.createElement('script')).src=url+'?%27+new%20Date().getTime();%7D)(
The URL must be like http://www.youtube.com/watch?v=KPtX7hak0Qs
https://www.
and replace with pwn
Example: