PHP 5.2.5 Using a simple script to test connection to MySQL (v5.0.45) installed on this new testbed running Apache 2.2.6 :
" <?php
mysql_connect("localhost", " ", "xxxx") or die(mysql_error());
echo "Connected to MySQL<br />";
?> "
The password is the same one I use when logging to MySQL from the client ( don't know how exactly to assure "username" is other than "no value" ). But I am still getting " Access denied for user 'ODBC'@'localhost' (using password: YES) " ; I've even tried omitting the username argument , no help.

This article should help:

http://forge.mysql.com/wiki/Error200...tToMySQLServer

A common problem can simply be forgetting to assign a user to your database in your Cpanel.

Double check your settings in the Cpanel