MYSQL Username and Password

{
    try
    {
        /*** connect to database ***/
        /*** mysql hostname ***/
        $mysql_hostname = 'localhost';

        /*** mysql username ***/
        $mysql_username = 'root';

        /*** mysql password ***/
        $mysql_password = 'azsx1234';

        /*** database name ***/
        $mysql_dbname = 'phpro_auth';


        /*** select the users name from the database ***/
        $dbh = new PDO("mysql:host=$mysql_hostname;dbname=$mysql_dbname", $mysql_username, $mysql_password);
      

Source: http://pastebin.com/raw.php?i=5dcYbNyM