Hi!
This happens because you use $_SERVER after an html output.
You shoud set a variable after
<?php
require("include/conexao.php");
$this_page=$_SERVER["PHP_SELF"] ;
....and in the form <form method="POST" action="<?php print $_SERVER["PHP_SELF"] ; ? >" (where you forgot to use the print constructor and the ";") ... And should work!
