Do you get blank pages?

Here is what I did...

Well what I did was look at the Amember logs for errors.
It gave me the following:
Cannot send headers; headers already sent in /home/******/public_html/member/application/configs/site.php, line 9
So what i found in that file at line 9 was this:

<?php
Am_Di::getInstance()->hook->add(am_Event::THANKS_PAGE, 'onThanksPage');
function onThanksPage(Am_Event $event){
$di = Am_Di::getInstance();
Am_Controller::redirectLocation('https://www.*******.com/thank-you.html');
}
/*?>
<?php */
Am_Di::getInstance()->hook->add(Am_Event::USER_AFTER_INSERT, 'onUserAfterInsert');
function onUserAfterInsert(Am_Event $event){
$user = $event->getUser();
$di = Am_Di::getInstance();
$ticket = $di->helpdeskTicketRecord;
$ticket->user_id = $user->user_id;
$ticket->status = HelpdeskTicket::STATUS_AWAITING_USER_RESPONSE;

///// TICKET SUBJECT
$ticket->subject = 'Welcome user '.$user->name_f.' '.$user->name_l;


$ticket->insert();
$message = $di->helpdeskMessageRecord;

$message->admin_id = 1; //// ADMIN ID

///// TICKET BODY
$message->content = 'Welcome to helpdesk. Simple content';



$message->ticket_id = $ticket->ticket_id;
$message->insert();

}

?>
My php programmer friend told me it was the "?> <?php " in the middle. How it got there i dont know, but when I commented it out, everything worked! No more blank pages.