Kan ikke se fejlen her

<?
session_start();

include("inc/tjek_login.php"); ?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
    <title>Post</title>
</head>

<body>
<?
if ($mappe == udbakke) {
/// Edit profile>>>
    echo"Udbakke!";
} elseif (!$mappe) {
/// When nothing is choosen>>>
include("inc/mysql.php");

$result = mysql_query("SELECT * FROM ld_user where username = '$username'") or die (mysql_error());
$row = mysql_fetch_array($result);
$result1 = mysql_query("SELECT * FROM ld_post where til = '$row[id]' && status = '1'") or die (mysql_error());
$number1 = mysql_num_rows($result1);
if ($number1 > "0") { echo "Der er $number1 ulæste breve i $row[navn] :<br><br>"; } else {
if ($number1 > "1") { echo "Der er $number1 ulæst brev i $row[navn] :<br><br>"; }

echo" <a href=\"post.php?mappe=indbakke\">Indbakke</a><p>";
echo" <a href=\"post.php?mappe=udbakke\">Udbakke</a><p>";

} elseif ($mappe == indbakke) {
  /// Indbakke>>>
    echo "Indbakke!";
   
}

?>
</body>
</html>


Den siger:

Parse error: parse error, unexpected T_ELSEIF in on line 31