Besucher Online ?

[Milchbox]

Ich weiss nicht wo dran es liegt aber es klappt nicht:

PHP-Code:

<?php
$db_hostname = "";
$db_username = "";
$db_passwort = "";
$db_database = "";
$tabelle ="onlineuser";
$online_time ="300";
$db = @mysql_connect($db_hostname, $db_username, $db_passwort) or die("Konnte Verbindung nicht herstellen: " . mysql_error());
@mysql_select_db($db_database, $db) or die("Konnte Datenbank nicht finden");
$uid = md5(uniqid(microtime()));
$ip = $_SERVER['REMOTE_ADDR'];
$dummy = "";
$result = mysql_query("SELECT ip FROM " . $tabelle." WHERE IP = '" . $ip . "'") or die(mysql_error());
if (mysql_num_rows($result) == 0) {
    $sqlQuery = sprintf("INSERT INTO %s (uid, ip, time) VALUES ('%s', '%s', '%s', '%s')",
        $tabelle,
        $uid,
        $ip,
        time()
    );
    mysql_query($sqlQuery) or die("Insert fehlgeschlagen: " . mysql_error());
}
$dtime = time() - $online_time;
@mysql_query("DELETE FROM " . $tabelle . " WHERE TIME < " . $dtime) or die(mysql_error());
$result = mysql_query("SELECT COUNT(IP) as total FROM " . $tabelle);
list($user_online) = mysql_fetch_array($result);
echo "es sind " . $user_online . " user online";
?>