I was about to type up a long answer on the fist thing to
check, and I
found this blog that does it all for me.
http://www.coldfusionguy.com/ColdFusion/blog/index.cfm/2007/11/13/CF8-AJAX-Features-CFIDEScripts-and...
To summarize, you need to make sure the CFIDE/scripts/ folder
is
properly accessible. You should be able to type the following
URL into
a browser, unless you have your site configured in a
non-default manner.
http://yourDomain/CFIDE/Scripts/cfform.js
I.E.
http://localhost/cfide/scripts/cfform.js
on *my* development server.
If that does not return a file, then none of the built in
ColdFusion
form or AJAX functionality is going to work.