struts2 + netbeans

Hi

I have small problem with examples from apache...
http://struts.apache.org/2.1.6/docs/how-do-we-repopulate-controls-when-validation-fails.html
because tomcat+netbeans show error:

org.apache.jasper.JasperException: tag 'select', field 'list', name
'language': The requested list key 'languages' could not be resolved as a
collection/array/map/enumeration/iterator type. Example: people or
people.{name} - [unknown location]

What is wrong?

Rf

---CODE--
**File: Languages.jsp
<%@ taglib prefix="s" uri="/struts-tags" %>
<s:select
   tooltip="Choose Your Favorite Language"
   label="Favorite Language"
   list="languages"
   name="language"
   listKey="key"
   listValue="description"
   emptyOption="true"
   headerKey="None"
   headerValue="None"/>

**File: Languages.java

import com.opensymphony.xwork2.ActionSupport;
import java.util.ArrayList;
import java.util.List;

public class Languages extends ActionSupport {
    public String execute() {
        languages.add(new Language("EnglishKey", "English Language"));
        languages.add(new Language("FrenchKey", "French Language"));
        languages.add(new Language("SpanishKey", "Spanish Language"));
        return SUCCESS;
    }

    List languages = new ArrayList();
    public List getLanguages() {
        return languages;
    }

    public static class Language {
        String description;
        String key;

        public Language(String key, String description) {
            this.key = key;
            this.description = description;
        }

        public String getKey() {
            return key;
        }

        public String getDescription() {
            return description;
        }

    }

}

**File: struts.xml:
<package name="myPackage" extends="struts-default">
  <!-- Public -->
              <action name="Languages" class="app.Languages">
                   <result>Languages.jsp</result>
                   <result name="Input">Languages.jsp</result>

              </action>

.....