php - mysql_connect() : Access denied for user 'user'@'localhost'

I am trying to connect to mysql and am getting an error.
I put my servers ip address in and used port 3306 whihch post should be used?

$connection = mysql_connect("serer.ip:port", "user", "pass")
 or die(mysql_error());


 if ($connection) {$msg = "success";}
?>

Here is the error its producing:

Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'user'@'localhost' (using password: YES) in /home/admin/domains/domain.com.au/public_html/db_connect.php on line 3
Access denied for user 'user'@'localhost' (using password: YES)

Answer

Use

$conn = mysql_connect($db_host,$db_user, $db_pass) or die("Error connecting to database");

The port is automatically selected as 3306.

Also double check to make sure your username and password for connecting are correct and allowed access.