connect db Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'root'@'localhost'

define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASSWORD', '1234');
define('DB_DATABASE', 'test'); 
define('DB_CHARSET', 'UTF8');

class myDatabase
{
  // stored database connection
  private $mMysqli;
  
  // constructor opens database connection
  function __construct()
  {
    $this->mMysqli = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE);
		$this->mMysqli->set_charset(DB_CHARSET);
  }

  // destructor closes database connection
  function __destruct()
  {
    $this->mMysqli->close();      
  }
}