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