You need to change those values to those of your MySQL User/DB accounts. Try the source below with your correct info (I commented it so you can follow):
CODE
<?php
$host = "localhost"; //host name - usually localhost
$user = "root"; //database username
$password = "root"; //database user password
$connection = mysql_connect($host, $user, $password) or die("Could not connect: ".mysql_error()); //grab the MySQL defined strings and insert them. Print result
echo "Connect to MySQL"; //only display is successfully connected
?>