[php] access denied for user @ 'localhost' to database ''

I'm seeing a lot of of similar questions to this. but can't find one exactly like mine yet. Not sure where to change these settings or anything, any help appreciated.

access denied Access denied for user ''@'localhost' to database ''

This is the beginning of my page.

$dbhost = 'localhost'; //unlikely to require changing.
$dbname ='publication'; //modify these
$dbuser = 'username'; //variables 
$dbpass = ''; //// to your installation
$appname = 'application name'; // and preference

mysql_connect($dbhost, $dbuser, $dbpass) or die(mysql_error());
mysql_select_db($dbname) or die(mysql_error());

You are most likely not using the correct credentials for the MySQL server. You also need to ensure the user you are connecting as has the correct privileges to view databases/tables, and that you can connect from your current location in network topographic terms (localhost).