Include header and footer into my cart

[tracievh]

I'm trying to include the header and footer into a shopping cart so that my site's look is consistent. I'm not very savy, and I assumed a php include would work. But it does not.

I basically did <?php require_once('wp-content/themes/lifestyle_40/header.php');?>
and the result was:
Fatal error: Call to undefined function bloginfo() in /home/beyondbo/public_html/wp-content/themes/lifestyle_40/header.php on line 5

line 5 of the header file is:
<meta http-equiv="Content-Type" content="<?php bloginfo('html_type'); ?>; charset=<?php bloginfo('charset'); ?>" />

I'm lost. I'm really hoping there is a way to do this.any help appreciated. Oh, if it matters, its squirrel cart.tracie