```php
<br />
<b>Warning</b>:  http_response_code(): Cannot set response code - headers already sent (output started at /homepages/35/d96013280/htdocs/ce/php/send_form.php:1) in <b>/homepages/35/d96013280/htdocs/ce/php/send_form.php</b> on line <b>15</b><br />
INVALID