WP-AJAX JS VARIABLE

Make wp-ajax url variable global:

function myplugin_ajaxurl() {
    echo '<script>
            var ajaxurl = "' . admin_url('admin-ajax.php') . '";
            var homeurl = "' . get_site_url() . '";
        </script>';
}
add_action('wp_head', 'myplugin_ajaxurl');