Database error after moving website?

I just moved my website from a test domain to the actual domain and I changed the DB info in the PHP script, but I'm still getting an error even though I triple-checked that I have the correct database, host, username and password. Am I missing something? This is the code I use to connect. The database info is definitely correct.

$dbhost = "localhost"; 

$dbuser = "username"; 

$dbpass = "password"; 



function dbConnect($db='dbname') {

    global $dbhost, $dbuser, $dbpass;



    $dbcnx = @mysql_connect($dbhost, $dbuser, $dbpass)

        or die('Database problem.');



    if ($db!='' and !@mysql_select_db($db))

        die('Database not available at the moment. Please try again in a couple of minutes.');



    return $dbcnx;

}

And then I call the function dbConnect('dbname') from the script. The error I get is the second error from the code above, "Database not available at the moment. Please try again in a couple of minutes.".

Can anyone see something I'm missing here?

EDIT:

The actual MySQL error is:

Access denied for user 'username'@'localhost' to database 'dbname'