Simple Theme - Internationalization problem

[Narayana S]

Hi,

        i am applying simple theme for my struts 2 page, when the theme is
default it could read values from resource bundle, after i changed theme to
simple, it couldn't read the values from the resource bundle.

<s:form action="SimpleAction" method="post"  theme="simple">
<s:label key="app.indexheader" />
---
</s:form>

This is how i am creating the form. am i missing any thing? please help me.