struts 2 validation - error message even after entering a value

[vibeeshan kambli]

Hi
I am new to struts 2 validation. I configured every thing correctly
even validation of the field works.
However some fields throws validation error message even after entering value.
but some of the other fields work fine

following field throws error

   <s:textfield name="firstName"  maxlength="30" cssClass="formlabel"/>

 however the following field works fine
<s:textfield name="address1"  maxlength="50" cssClass="formlabel"/>

I am using simple theme. Any help is greatly appreciated . thank you

[Jesus Mireles]

What validation annotations or configs did you set? What error do you get?