source: trunk/www.guidonia.net/wp/wp-content/themes/atahualpa/functions/bfa_search_widget.php@ 44

<?php // create new search widget
function widget_search($args) {
        extract($args);
        $searchform_template = get_template_directory() . '/searchform.php';
        
        echo $before_widget;
        
        // Use current theme search form if it exists
        if ( file_exists($searchform_template) ) {
                include_once($searchform_template);
        } else { ?>
                <form id="searchform" method="get" action="<?php bloginfo('url'); ?>/"><div>
                        <label class="hidden" for="s"><?php _e('Search for:','atahualpa'); ?></label>
                        <input type="text" name="s" id="s" size="15" value="<?php the_search_query(); ?>" />
                        <input type="submit" value="<?php echo attribute_escape(__('Search','atahualpa')); ?>" />
                </div></form>
<?php }
        echo "</div>";
}
?>
<?php // unregister old / register new search widget
        $widget_ops = array('classname' => 'widget_search', 'description' => __( "A search form for your blog","atahualpa") );
        unregister_sidebar_widget('search', __('Search','atahualpa'), 'wp_widget_search', $widget_ops);
        wp_register_sidebar_widget('search', __('Search','atahualpa'), 'widget_search', $widget_ops);
?>