Which request is used in Validation when the requirements aren't met?

[Thai Dang Vu]

Hello everybody,
 
This is my action declaration in struts-config.xml
 
    <action path="/add_provider"
            type="AddProviderAction"
            name="addProviderForm"
            input="/WEB-INF/provider/addprovider.jsp"
            validate="true"
            scope="request">
    </action>
 
In addprovider.jsp page, when I click 'Submit' and the requirements aren't met, 
the request is forwarded to the input (which is 
/WEB-INF/provider/addprovider.jsp). How and where can I get the request before 
the input page appears (so that I can put something in the request to make the 
input displays correctly)?
 
Thanks.