IE6 problem finding YAHOO in YUI application

I have a page that uses the YUI tree view that links to specific
fields in a displayed document.
It works fine in Firefox (of course 8-) and IE7, but clicking on the
nodes in IE6 does not work.
If I try and open the link in a new window, I get

Error: 'YAHOO" is undefined
Code: 0
URL: javascript:YAHOO.widget.TreeView.getNode('toc',3). toggle()

Any ideas?

wrote on 27 aug 2008 in comp.lang.javascript:
Simple: Define YAHOO.

Warning: The fruit of the YUI tree could be poisonous!

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

On Aug 27, 8:15*am, stacey1112...@gmail.com wrote:Post questions about this to the YAHOO YUI mailing list (in YAHOO!
Groups), and show enough detail of your code for someone to get a clue
to what's wrong.