Exception in thread "main" ......java.lang.ClassNotFoundException

plus about half a page of other data.
 
I am running thus:
java -jar css-validator.jar [myfilename]
(it doesn't seem to matter what filename I give it, or even
'http://www.w3.org/")
 
The instructions (at  <http://jigsaw.w3.org/css-validator/DOWNLOAD.html>
http://jigsaw.w3.org/css-validator/DOWNLOAD.html) say:
Any computer with Java installed can also run the validator from the
terminal/console as a commandline tool. Download the css-validator.jar jar
archive (or build it with ant jar) and run it as :
java -jar css-validator.jar  <http://www.w3.org/> http://www.w3.org/.
Note : the css-validator.jar file must be located at the exact same level as
the lib/ folder to work properly.

Which "lib/" folder????
 
John Turner
Burgh House Limited, Business Solutions      Just imagine . . .
 <http://burghhouse.com/> http://burghhouse.com
 (+290) 22944
NOTICE TO RECIPIENTS:  This communication and any attachments are
confidential, meant solely for the intended recipient of the transmission,
and may be a communication privileged by law. Access to this by anyone else
is unauthorised. If you received this communication in error or are not the
intended recipient, any review, use, dissemination, distribution, copying of
this communication or any action taken or omitted to be taken in reliance on
it, is strictly prohibited and may be unlawful. If you have received this
communication in error, please notify the author by reply and then kindly
delete the communication. Thank you.
Please save trees: only print this email where absolutely necessary.