Simple Evaluator doesn't work...Java class not found

[dave984]

Referring to this article on the Alfresco Documentation, i'm trying to load a simple evaluator to hide a component in the UI:
http://docs.alfresco.com/4.2/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Ftasks%2Fdev-extensions...

I'm using Alfresco 4.2.c Community and i think i have deployed all successfully:
- Java classes in a jar in C:\Alfresco\tomcat\webapps\alfresco\WEB-INF\lib
- extension-modules.xml in C:\Alfresco\tomcat\webapps\share\WEB-INF\classes\alfresco\site-data\extensions
- spring-surf-extensibility-context.xml in C:\Alfresco\tomcat\webapps\share\WEB-INF\classes\org\springframework\extensions\surf

Share won't start[HTTP Status 404 - /share] and this is the error in the alfrescotomcat-stdout:

2014-03-04 12:42:33,197  ERROR [web.context.ContextLoader] [localhost-startStop-1] Context initialization failedorg.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [it.evaluator.SiteMembersEvaluator] for bean with name 'beans.evaluator' defined in file [C:\Alfresco\tomcat\webapps\share\WEB-INF\classes\org\springframework\extensions\surf\spring-surf-extensibility-context.xml]; nested exception is java.lang.ClassNotFoundException: it.evaluator.SiteMembersEvaluator‍‍‍‍‍‍‍

Please give me some hints to make it work!!

[dave984]

Basically, this statement was wrong: "Java classes in a jar in C:\Alfresco\tomcat\webapps\alfresco\WEB-INF\lib".
The jar file have to be there and in: C:\Alfresco\tomcat\webapps\share\WEB-INF\lib

Now, if i have a module introdued in document detail's page and i want to hide it in case the document is in a certain folder…
How retrieve the nodeRef.parent information?
I cannot use Java API from Share Tier…have i call a webscript to do this?
I cannot simply have this information in another way?