Hidden page dilema

Hello,

I’m trying to hide my Thank You page and am running into an issue.

I understand that the html in the post-template.php needs to be alter under wp_list_pages.

So I created my page- took note of the ID

Altered the following code:

function wp_list_pages($args = '') {
	$defaults = array(
		'depth' => 0, 'show_date' => '',
		'date_format' => get_option('date_format'),
		'child_of' => 0, 'exclude' => '',
		'title_li' => __('Pages'), 'echo' => 1,
		'authors' => '', 'sort_column' => 'menu_order, post_title',
		'link_before' => '', 'link_after' => '', 'walker' => '',

	);

to

function wp_list_pages($args = '') {
	$defaults = array(
		'depth' => 0, 'show_date' => '',
		'date_format' => get_option('date_format'),
		'child_of' => 0, 'exclude' => '98',
		'title_li' => __('Pages'), 'echo' => 1,
		'authors' => '', 'sort_column' => 'menu_order, post_title',
		'link_before' => '', 'link_after' => '', 'walker' => '',

	);

yet page is still showing??? It worked out fine with my test site, so not sure why I can’t work it out with this one.

Any ideas was I may have missed?

Thanks!