Problem with database!

PDOException: SQLSTATE[28000] [1045] Access denied for user 'hatelzrs'@'localhost' (using password: NO) in /home/hatelzrs/public_html/class/database.php:8
Stack trace:
#0 /home/hatelzrs/public_html/class/database.php(8): PDO->__construct()
#1 /home/hatelzrs/public_html/index.php(7): DataBase->__construct()
#2 {main}