login side.

hvorfor kan jeg ikke se siden når jeg logger ind.

<?php
include("db.php");
session_start();
if (isset($_POST['logind'])) {

    $queryadmin = mysql_query("SELECT COUNT(id) FROM admin WHERE user='$_POST[nick]' AND pass='$_POST[pass]'");
    $admin = mysql_fetch_array($queryadmin);
    if ($admin['0'] > 0) {
        $_SESSION['aid'] = 1;
        header("Location: secret.php");
        exit;
    }
}   
?>

<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
Brugernavn: <input type="text" name="nick"><br/>
Kodeord: <input type="password" name="pass"><br/>
<input type="submit" name="logind" value="Log ind">
</form>