Javascipt code I can't understand

[whackeddragon]

I am trying to recreate an effect using a Javascript tutorial.. it seems basic enough but I can't get my head around it. This is the link;
http://gsgd.co.uk/sandbox/jquery/easing/

and this is kinda what I want it to look like;
http://gsgd.co.uk/freelance/

anyone help me