Javascript Newbie Trouble - please help!

Hi there,

Apologies if I've missed something totally obvious here, I'm totally wet behind the ears when it comes to scripting. I've got this pretty cool looking script off Javascript Source:

http://javascript.internet.com/navigation/slide-down-menu.html

It's an expandable menu installed by popping the code into the body of the html page, which I did. When I view the page in a browser, there's no menu. I only get the Javascript Source link message at the bottom of the script.

It's from a reliable source, and I just know I've done something dead obvious to mess it up... but can't figure out what for the life of me. The only thing that occurs to me is that it seems to reference another file or routine that isn't part of the script: <script language="JavaScript" src="sliding_menu.js"></script>

I could be way out with that though!

If anyone can offer their expertise, I would be well, well, well grateful. I really want to get it working!

Thanks!

Martin.

Ps. I put a copy of the page that isn't working here:

[URL= [url]http://www.theretropostershop.com/Menu.htm][/url] http://www.theretropostershop.com/Menu.htm[/URL]

It's in it's simplest form, an html page with the script pasted in the body. A tag was part of the script, creating a second on the page. (I tried removing it - it made no difference.) I left both tags in the uploaded page, which one should I use?

I also put the original script up in html in case anyone would be kind enough to check it:

http://www.theretropostershop.com/OriginalScript.htm