slide javascript not working

I have been trying to get this script (http://www.harrymaugans.com/2007/03/06/how-to-create-an-animated-sliding-collapsible-div-with-javascript-and-css/)
to work in my blog.It works on a simple html page but not when i apply the same code in the blog.I followed the directions in codex page for putting javascript in the page but it still doesnt work. Do i have to create a special function to do it and if yes can someone show me how to do it since I am a newbie to wp and javascript.thanks