Add custom html after the_content in Wordpress

Add after content WP

<?php
    function insertFootNote($content) {
        if(!is_feed() && !is_home()) {
            $content.= "<div class='subscribe'>";
            $content.= "<h4>Enjoyed this article?</h4>";
            $content.= "<p>Subscribe to our  <a href='http://feeds2.feedburner.com/WpRecipes'>RSS feed</a> and never miss a recipe!</p>";
            $content.= "</div>";
        }
        return $content;
    }
    add_filter ('the_content', 'insertFootNote');
    // You can use the_exerpt, the_title, ...
?>