Validate Comment Form on the Fly?

Hi, can I edit my comments form to check for name and e-mail on the fly, rather than going to the default wp-comments-post.php when somebody misses a field?

If not how can I edit the look of this default error page, it looks empty and doesn’t fit in with my page and just says:
“Error please fille the required fields (name, email).”

EDIT: Resolved via plugin