Custom Error message in portal

HI Experts,

I trying to implement cutom error messages in portal. By Following the below link.

[https://cw.sdn.sap.com/cw/community/docupedia/nw70java/blog/2010/03/21/custom-error-messages-in-the-portal]

As of now I trying to implement it for error code "500".

<error-page>
             <error-code>500</error-code>
             <location>/Customerrors/500.html</location>
       </error-page>
</web-app>

The above code I pasted in web.xml. 500.html is there in customerrors folder. I have also restrated the system.

when I log in to portal system still I could see standard message coming for "500" code error not the custom one from 500.html.

Iam using EP7.0 EHP1 .

Thanks

Surender Singh Dahiya