basic php form question

I need some help with the following code.

the current code makes the "frontpage.php" appear if the checkbox "frontpage" is checked. This works fine

if(isset($frontpage)) {include ('includes/frontpage.php');}

but How do I do a similar example if I want a value to be shown from another file if the checkbox is checked.

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config file
$information = "This is the information I need";

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Form
<input name="frontpage" type="checkbox" value="frontpage">

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process page.
if(isset($frontpage)) echo" $information";