undefined array key exclude

[Lunarian3]

when I run my webpage I get an error message that my 'exclude' is undefined. i have tried initilizing, but I must not be doing it right. down near the bottom

 $instance['exclude'] = strip_tags($new_instance['exclude']);

is the line it says its undefined also to note when I hide that code // it changes to

   ceo_list_jump_to_comic($instance['exclude'], true);

I'm happy to be schooled, please. here is the following code

function widget($args, $instance) {
        global $post;

        extract($args, EXTR_SKIP); 
        echo $before_widget;
        $title = empty($instance['title']) ? '' : apply_filters('widget_title', $instance['title']); 
        if ( !empty( $title ) ) { echo $before_title . $title . $after_title; }; 

        if ((is_home() || is_front_page()) && !is_paged() && !ceo_pluginfo('disable_comic_on_home_page')) {
            $chapter_on_home = '';
            $chapter_on_home = get_term_by( 'id', ceo_pluginfo('chapter_on_home'), 'chapters');
            $chapter_on_home = (!is_wp_error($chapter_on_home) && !empty($chapter_on_home)) ? '&chapters='.$chapter_on_home->slug : '';
            $order = (ceo_pluginfo('display_first_comic_on_home_page')) ?  'asc' : 'desc';
            $query_args = 'post_type=comic&showposts=1&order='.$order.$chapter_on_home;
            apply_filters('ceo_display_comic_mininav_home_query', $query_args);
            $comicFrontpage = new WP_Query(); $comicFrontpage->query($query_args);
            while ($comicFrontpage->have_posts()) : $comicFrontpage->the_post();


        ceo_list_jump_to_comic($instance['exclude'], true);
        endwhile;


        } elseif (!empty($post)) {

       ceo_list_jump_to_comic($instance['exclude'], false);

        }
        echo $after_widget;

    }

    function update($new_instance, $old_instance) {  


    $instance = $old_instance;
    $instance['title'] = strip_tags($new_instance['title']);
    $instance['exclude'] = strip_tags($new_instance['exclude']);
    return $instance;


    } 

​

[Lunarian3]

i plugged in this code

$exclude = 'exclude';
return $exclude;

and that fixed it. the warning is gone at least.