field

// Add extra field to comment form
function add_bcw_fields($fields){
   $fields['test'] = '<input type="text" name="test" id="test" size="22" />';
   return $fields;
}
add_filter( 'comment_form_default_fields', 'add_bcw_fields' );
//Save the extra comment field value
function bcw_handle_comment($id) {
   if (array_key_exists('test', $_POST))
      update_comment_meta( $id, 'bcw_test', $_POST['test']);
}
add_action('wp_insert_comment', 'bcw_handle_comment');
//Override default theme function to display a comment

function twentyten_comment( $comment, $args, $depth ) {
    $GLOBALS['comment'] = $comment;
    switch ( $comment->comment_type ) :
        case '' :
    ?>
    <li <?php comment_class(); ?> id="li-comment-<?php comment_ID(); ?>">
        <div id="comment-<?php comment_ID(); ?>">

            <div class="comment-author vcard">
                <?php echo get_avatar( $comment, 40 ); ?>
                <?php printf( __( '%s <span class="says">says:</span>', 'twentyten' ), sprintf( '<cite class="fn">%s</cite>', get_comment_author_link() ) ); ?>
            </div><!-- .comment-author .vcard -->
            <?php if ( $comment->comment_approved == '0' ) : ?>
                <em class="comment-awaiting-moderation"><?php _e( 'Your comment is awaiting moderation.', 'twentyten' ); ?></em>
                <br />
            <?php endif; ?>

            <div class="comment-meta commentmetadata"><a href="<?php echo esc_url( get_comment_link( $comment->comment_ID ) ); ?>">
                <?php
                    /* translators: 1: date, 2: time */
                    printf( __( '%1$s at %2$s', 'twentyten' ), get_comment_date(), get_comment_time() ); ?></a><?php edit_comment_link( __( '(Edit)', 'twentyten' ), ' ' );
                ?>
            </div><!-- .comment-meta .commentmetadata -->

            <div class="comment-body"><?php comment_text(); ?></div>
                         <?php echo get_comment_meta( $comment->comment_ID, 'bcw_test', true ); ?>

            <div class="reply">
                <?php /* <?php comment_reply_link( array_merge( $args, array( 'depth' => $depth, 'max_depth' => $args['max_depth'] ) ) ); ?> */ ?>
            </div><!-- .reply -->
        </div><!-- #comment-##  -->

    <?php
            break;
        case 'pingback'  :
        case 'trackback' :
    ?>
    <li class="post pingback">
        <p><?php _e( 'Pingback:', 'twentyten' ); ?> <?php comment_author_link(); ?><?php edit_comment_link( __( '(Edit)', 'twentyten' ), ' ' ); ?></p>
    <?php
            break;
    endswitch;
}
endif;