I dont get to use dwr.engine.setTextHtmlHandler

Hi people,

I started to work with dwr and spring. I setting all configuration files as follow:

<!-- DWR Setting --> 
    <filter>
        <filter-name>requestContextFilter</filter-name>
        <filter-class>org.springframework.web.filter.RequestContextFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>requestContextFilter</filter-name>
        <url-pattern>/dwr/*</url-pattern>
    </filter-mapping>
   
   
    <servlet>
      <servlet-name>dwr</servlet-name>
          <servlet-class>org.directwebremoting.spring.DwrSpringServlet</servlet-class>
          <init-param>
            <param-name>debug</param-name>
            <param-value>true</param-value>
      </init-param>
      <init-param>
            <param-name>allowScriptTagRemoting</param-name >
            <param-value>true </param-value>
          </init-param>
          <init-param>
            <param-name>activeReverseAjaxEnabled</param-name>
            <param-value>true</param-value>
          </init-param>
    </servlet>

    <servlet-mapping>
      <servlet-name>dwr</servlet-name>
      <url-pattern>/dwr/*</url-pattern>
    </servlet-mapping>
<!-- End -->   

applicationContext:

    <bean id="facade" class="com.brightstar.toms2.control.facade.AjaxFacadeImpl" scope="request">
       <dwr:remote javascript="RemoteAjaxFacade">
           <dwr:include method="getNames"/>
       </dwr:remote>
    </bean>

    <dwr:configuration>
        <dwr:convert type="bean" class="com.brightstar.common.util.SelectItems" />
    </dwr:configuration> 

and  my test jsp page ' s scripts  :

.
.
.

dwr.engine.setActiveReverseAjax(true);
    dwr.engine.setTextHtmlHandler(function() {
            window.alert("Your session has expired, please login again." );
    });
   
    function fillChild() {
          var select = dwr.util.getValue("parent");
        RemoteAjaxFacade.getNames(select, function(selectItems) {
                    dwr.util.removeAllOptions("child");
                    dwr.util.addOptions("child",selectItems,"id","nome");

            }
        );
      }


Almost all works perfectly, but when the session ends, it´s possible to do request by ajax yet. Never is called "window.alert("Your session has expired, please login again." );"

What I did wrong ?

regards
Marlus Misael