How to add script into page/forum?

How can i add this to xenforo?

<script type="text/javascript" src="scrolltopcontrol.js">

Where to place this... I tried some thing but didn't work for me!

PAGE_CONTAINER and page_container_head_js...

Anyone can help me out with this?


Yeah but the strange thing normal html is working but in xenforo <a href='#top'>top</a> it don't picks up the jquery somehow:S when i put a normal html page its working... the .js file is there also!