Answer for Send button not working in forms

Hi
Trying to dig into this way, I found that there was a kind of hidden field I copied by mistake form Mailchimp to the newsletter code of template-home. When I remove it, I still got the 500 error in Firebug, but on newsletter.php this time.
Looking at newsletter.php content I found this which looks like a keyboard mistyping to me :

if ( ! empty( $subscriber[‘leid’] ) ) {
   echo “success”;
}
else {
    echo “fail”;
}

Is ‘leid’ correct?

Thank you.