Ошибка mysql_real_escape_string при обращении к БД

Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: Access denied for user 'u141981214'@'10.2.1.16' (using password: NO) in /home/u141981214/public_html/functions.php on line 420
 
Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: A link to the server could not be established in /home/u141981214/public_html/functions.php on line 420
 
Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: Access denied for user 'u141981214'@'10.2.1.16' (using password: NO) in /home/u141981214/public_html/functions.php on line 189
 
Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: A link to the server could not be established in /home/u141981214/public_html/functions.php on line 189

$login=mysql_real_escape_string($login);

query("SET NAMES 'utf8'");

    $login=mysql_real_escape_string($login);
    $query = $db->prepare("SELECT * FROM users WHERE Name='$login'");

$connection = mysql_connect("host","user","pass");
mysql_select_db("dbname",$connection);
echo mysql_real_escape_string("string to be escaped",$connection);

 
$login=$_POST['name'];
$pass=$_POST['pass'];
connect_db($hostname, $username, $password, $name_bd, $type_bd);
password($login, $pass);
 
function connect_db($hostname, $username, $password, $name_bd, $type_bd){
    // объявляем глобальной переменную
    global $db;
    if ($type_bd==1){
        try{
                  // подключаемся к базе
            $db = new PDO("mysql:dbname=$name_bd; host=$hostname", $username, $password);
            // устанавливаем нужную кодировку
            $res = $db->query("SET NAMES 'utf8'");
        }
        catch(Exception $e){
 //             die( print_r( $e->getMessage() ) );
            die (" ERROR connect MySql");
        }
    }
}
 
function password($login, $pass) {
...
    $login=mysql_real_escape_string($login);
    $query = $db->prepare("SELECT * FROM users WHERE Name='$login'");
...