some help

[AN-net]

heres where it originates from: the $a comes from a link

PHP Code:

<?PHP
error_reporting(E_ALL & ~E_NOTICE);
include('./global.php');
$globaltemplates = array(
'STANDARD_REDIRECT',
'STANDARD_ERROR',
);
$fsettings= $DB_site->query("SELECT * FROM affiliates_settings");
$settings= $DB_site->fetch_array($fsettings);

if($_REQUEST['do']=="image"){
if(empty($_REQUEST['a'])){
header("Location: $vboptions[bburl]/images/error.gif");
}
else{
header("Location: $settings[imagelink]");
}
}