how to add validations in mini-login form without redirecting in header itself of magento -

i using default mini-login form in header , works logged in correct details whenever enter wrong username , password validation redirects customer/login page don't want use. want validations customer/login page in header , don't want redirect anywhere. please give suggestion.

i found answer myself validations below : in form tag have added id :

<form action="<?php echo $this->getpostactionurl() ?>" method="post" id="login-form-header"> 

then put below script validate

<script type="text/javascript"> //<![cdata[     var dataform = new varienform('login-form-header', true); //]]> </script> 

and required classes in input box question :
when both fields validate , email, password not matching redirects customer/login page don't want redirect , should stay on same.