Mysqli Connection with PHP

我正在努力连接到mysql，到目前为止，我结束了这个错误:

  Warning: mysqli_connect(): (HY000/1045): Access denied for user 'dev'@'localhost'         (using password: YES) in D:'Programs'Xamp'htdocs'series'dynamic'AtomCMS'setup.php on line 5
Could not connect because: Access denied for user 'dev'@'localhost' (using password: YES)

我刚刚开始开发一个新的基于web的系统，这里是我用来连接到数据库的代码。任何帮助都是感激的。

$dbc = mysqli_connect('localhost','dev','123','pouya')OR die('Could not connect because: '.mysqli_connect_error());