Customising Error pages in EP

hi experts ,

Im using SAP EP 7.01 Enhancement package 1 , i have gone through this link http://scn.sap.com/thread/1423140  for customizeing error pages , i have followed the step where

i placed customised error pages in Error_Pages folder as specified in the blog and then went to webinf folder and edited web.xml file ,

here i didnt see any occurances of error tags i.e.  <error-page> ....

still i pasted the code as

<error-page>
  <error-code>404</error-code>
  <location>/Error_Pages/404.html</location>
</error-page>

<error-page>
  <error-code>403</error-code>
  <location>/Error_Pages/403.html</location>
</error-page>

<error-page>
  <error-code>500</error-code>
  <location>/Error_Pages/500.html</location>
</error-page>

but even after restarting the server above change is not reflected, ie for 404 or 403 standard sap error page is getting displayed instead of customised 403.hmtl or 404.html

Regards

Govardan Raj