Dashboard executes php file, wrongly

I am trying to follow along with a book to learn theme coding – “Sitepoint.com – Build Your Own Wicked WordPress Themes”.

I’m trying to register a widget-ready area for the theme I have been working with, Thematic. The book says I need to add

include('library/widget-areas.php');

to my functions.php file, and this include will call up a subsequent php file,

<?php
// Register the extra Footer Aside
function wicked_footer_aside() {
register_sidebar(array(
'name' => 'Main Footer Aside',
'id' => 'footer-aside',
'description' => __('A widget area in the footer, above the subsidiary
➥asides.', 'thematic'),
'before_widget' => thematic_before_widget(),
'after_widget' => thematic_after_widget(),
'before_title' => thematic_before_title(),
'after_title' => thematic_after_title(), )
);
}
add_action('init', 'wicked_footer_aside');
?>

My question is, whenever I write my include code into my functions.php, My dashboard gets screwed up by including (displaying) that php file in almost every header of my dashboard – http://coreylight.com/docs/error.JPG

What am I doing wrong? (I have tried to look up this answer on my own somehow, but I can’t figure out how to phrase it correctly)