Boh, sul server non ho problemi mi funziona tutto...

Cmq eccolo.

codice:
<?
session_start();
sess_gc($SESS_LIFE);
if (isset($_SESSION['username'])) header("location:index.php?action=login_index&cdf=".time());

if ($Submit && $username && $password) {
	$query="SELECT * FROM account WHERE username='$username' AND password='$password'";
	$result = mysql_query($query);
	if (mysql_num_rows($result)>0) {
		$row = mysql_fetch_assoc($result);
		mysql_free_result ($result);
		session_start();
		session_register("username");
		session_register("password");
		header("location:index.php?action=login_index&cdf=".time());
		exit;
	}
	$h_msg="<p align='center'>Nome utente o password sbagliati.</p>\n";
}
session_destroy();
?>

<?=$h_msg?>

<DIV align="center">
<FORM name="login" method='post' action="?action=login">
<TABLE width="50%" border="0" cellspacing="0" cellpadding="3" align="center">
  <TR>
    <TD align="right">Username</TD>
    <TD><INPUT name="username" type="text" id="username"></TD>
  </TR>
  <TR>
    <TD align="right">Password</TD>
    <TD>
        <INPUT name="password" type="password" id="password">
      </TD>
  </TR>
  <TR>
    <TD></TD>
    <TD><INPUT type="submit" name="Submit" value="Login"></TD>
  </TR>
</TABLE>
</FORM>
</DIV>