[SOLVED] where can I edit php script morning, day and night header without lossing my

I got this php script and I works perfectly:

<img src="http://www.lasvegascity.nl/wp-content/themes/atahualpa/images/header/header_<?php
$hour = date('Hi'); // hour of the day, 24 hour clock
if ($hour > 1759 or $hour < 600) {
$timepic = 'night';
} elseif ($hour > 1200) {
$timepic = 'day';
} else {
$timepic = 'morning';
}
echo $timepic;

?>.png">

But when I change <?php echo bfa_header_config(); ?> in header.php, the menu wil disapear. Where can I put this php code so my menu won't disapear?