Select Add: Google vs Adserver

<?php

$isGoogleActive = 1;
$adHeight = $_GET['adHeight'];
$adWidth = $_GET['adWidth'];
$adSource = $_GET['adSource'];
$advertiser = $_GET['advertiser'];

$folder = ($advertiser!='')? $advertiser:'google';

switch($isGoogleActive){
case 1:
include("$folder/{$adWidth}{$adHeight}.php");
echo("$folder/{$adWidth}{$adHeight}.php");
?>
<?php
break;
case 0:
include("adserver/{$adWidth}_{$adHeight}.php");
break;
}

?>