NIe wiem co jest zle ale wywala mi blad

<?php
$mysql_host="localhost";
$mysql_user="******";
$mysql_pass="******";
$mysql_db="*******";
// Ustawienia //
$mail = $_POST["mail"];
$notatka = $_POST["notatka"];
$pass = $_POST["pass"];
mysql_query("INSERT INTO notatka VALUES ('', '".$id_uzytkownika."', '".$notatka."');");
?>
A tutaj blad
Warning: mysql_query(): Keine Zugriffsberechtigung für Benutzer: 'www-data@localhost'. (Verwendetes Passwort: Nein) IN /var/www/vhosts/********/httpdocs/notator/napisz.php ON line 23
Warning: mysql_query(): A link TO the server could NOT be established IN /var/www/vhosts/********/httpdocs/notator/napisz.php ON line 23
?>