/**
 * Move Comment field to bottom
 */
if ( !function_exists( 'appmax_move_comment_field_to_bottom' ) ) :
    function appmax_move_comment_field_to_bottom( $fields ) {
        $comment_field = $fields['comment'];
        unset( $fields['comment'] );
        $fields['comment'] = $comment_field;
        return $fields;
    }
endif;
add_filter( 'comment_form_fields', 'appmax_move_comment_field_to_bottom' );