找不到密码怎么回事

Notice: Undefined variable: password in D:\PHPTutorial\WWW\mypage.php on line 14

Warning: mysqli_connect(): (HY000/1045): Access denied for user 'root'@'localhost' (using password: NO) in D:\PHPTutorial\WWW\mypage.php on line 14
数据库连接失败