Insert generic code on every page

Hi Guys,

Is there a way in inserting blocks of code on every page?

For instance, I want to set up a multi-page editor called "snippets" which are going to be a whole bunch of bits and peices that will be displayed at various places aroun the site.

So the code to place at the start of the page is:

<?php header('Content-type: text/html; charset=utf-8'); ?>
<?php

require_once "/cmsAdmin/lib/viewer_functions.php";

list($snippetsRecords, $snippetsMetaData) = getRecords(array(
'tableName' => 'snippets',
));

?>

And then there are others that I use constantly through the site... categories, newlist, blog_comments etc.

Rather than placing each of these blocks of text on each page, and making changes to every page when something changes... can I add the following?

<?php
include("_insertSiteWideCode.php");
?>

where insertSiteWideCode.php is;
<?php

require_once "/var/www/forrest.id.au/public_html/nutsDemo/lib/viewer_functions.php";

list($a_text_snippetsRecords, $a_text_snippetsMetaData) = getRecords(array(
'tableName' => 'a_text_snippets',
));

list($b_latest_newsRecords, $b_latest_newsMetaData) = getRecords(array(
'tableName' => 'b_latest_news',
'perPage' => '5',
));

list($c_galleryRecords, $c_galleryMetaData) = getRecords(array(
'tableName' => 'c_gallery',
'perPage' => '5',
));

?>

I try, and get "Warning: session_start(): Cannot send session cache limiter - headers already sent..."