Going to start using fopen(), fwrite() etc. to help people edit their files on their sites.

Its going to show different areas of the file in textboxes, so the user can change them, and click 'save'

How do I select a certain portion of the file (code) to display in these textboxes?

Preg_Match would be the best way.
http://uk.php.net/manual/en/function.preg-match.php

PHP Code:

<?php
$subject = "abcdef"; // this would be the file contents
$pattern = '/^somethingthatmakesyoucodestandout/';
preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE);
print_r($matches);
?>

Hope this helps

Also, take a look at file_put_contents ( http://uk.php.net/manual/en/function...t-contents.php ) it saves a bit of coding time.

Thanks, but what if its not always the same thing inside the div. As this part will be always changing