Your connection method should look something like this:
$host = ###.###.###.### The IP address of the mysql server (localhost is a reference to your machine 127.0.0.1
$user/$password = Your login credentials
$db = the database assigned to you by your host, probably something including you name, or just a serial number...
$port = if the host gave you a specific port ot use
$sock = if the hot gave you a specific socket to use
All of these values should have been provided when you signed up for an account. Probably in an email somewhere
$link = mysql_connect($host, $user, $password, $db, $port/sock);