Erro no Struts

package br.com.thiago.struts.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class ActionSimples extends Action{
	
	public ActionForward execute(ActionMapping map, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception{
		
		System.out.println("Running...");
		return map.findForward("ok");
	}

}

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE struts-config PUBLIC
	"-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
	"http://struts.apache.org/dtds/struts-config_1_2.dtd">

<struts-config>

	<action-mappings>
		
		<action path="/teste" type="br.com.thiago.struts.action.ActionSimples">
			<forward name="ok" path="/exemplo.jsp"/>
		</action>
		
	</action-mappings>
	
	<!-- Arquivo de Mensagens -->
	<message-resources parameter="MessageResources"/>
	
</struts-config>

<?xml version="1.0" encoding="ISO-8859-1"?>  
<web-app xmlns ="http://java.sun.com/xml/ns/j2ee" version="2.4">
	
	<servlet>
		<servlet-name>action</servlet-name>
		<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
		<init-param>  
			<param-name>config</param-name>  
			<param-value>/WEB-INF/struts-config.xml</param-value>  
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	
	<servlet-mapping>
		<servlet-name>action</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>
	
</web-app>

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.ClassNotFoundException: br.com.thiago.struts.action.ActionSimples
	org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:286)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

root cause

java.lang.ClassNotFoundException: br.com.thiago.struts.action.ActionSimples
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1360)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1206)
	org.apache.struts.chain.commands.util.ClassUtils.getApplicationClass(ClassUtils.java:54)
	org.apache.struts.chain.commands.util.ClassUtils.getApplicationInstance(ClassUtils.java:71)
	org.apache.struts.chain.commands.servlet.CreateAction.createAction(CreateAction.java:98)
	org.apache.struts.chain.commands.servlet.CreateAction.getAction(CreateAction.java:68)
	org.apache.struts.chain.commands.AbstractCreateAction.execute(AbstractCreateAction.java:90)
	org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
	org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
	org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
	org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
	org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.16 logs.