Custom Field Array returning extra content – Why?

I’m not a PHP guy, but I pieced together this script. It works, but it returns extra content… in the for of the number “1”.

<?php
$sidemodule_values = get_post_custom_values('sidemodule'); 

if ($sidemodule_values[0]=="") {
include(TEMPLATEPATH . "/sidemodules/test3.php");
include(TEMPLATEPATH . "/sidemodules/test4.php");
}
else {
foreach ( $sidemodule_values as $key => $value )
    echo include(TEMPLATEPATH . "/sidemodules/$value.php");
}
?>

I have two instances of the “sidemodule” custom field set up on a page with values of “test1″ and test2”. Here’s what I get back when the page is rendered:

<p>content (from test1.php)</p>1<p>content (from test2.php)</p>1

Everything works fine in terms of the content from the two external files is being displayed, but each block is followed by “1”.

I’ve tried several variations and I can’t figure out why. Any suggestions would be appreciated.

Basically I’m setting up a sidebar that will have default content that will be included unless custom fields have been applied to override it.