Adding script using wp_enqueue_script

Can someone please provide me with some detailed instructions on how to add this banner script to my header.php, And exactly what to add the functions.php
http://creepychrisproductions.nfshost.com/scripts/hedr.html
using wp_enqueue_script
I cant figure out how to do this, the only way I can get this header to work is to copy the script directly to the header.php but I have been trying to do it the right way for the past 15 hours and I cant figure it out…
The website is located here, http://creepychrisproductions.nfshost.com