Modify DB script to connect

[Mork Heng]

i have migrate to a multiple domains server which doesn't have cgi-bin for each domain n doesn't support ODBC. So i have to modify a script written long ago by someone (top part of the script the help line ask me to modify):

use strict;
use DBI;
use CGI::Carp qw(fatalsToBrowser);

my $dbstring = 'dbi:ODBC:Castle_de_France';
#my $dbstring = 'dbi:mysql:db';
my $dbstring = 'dbi:mysql:castle';
my $user = 'cdef;
my $pass = 'france';

my $IsMSQL = 1;

sub IsMySQL(){ return $IsMSQL; }

sub getLastInsertId(){
my $lastInsertIdSQL;

if (&IsMySQL()) {
$lastInsertIdSQL = 'select last_insert_id() id';
} else {
$lastInsertIdSQL = 'select @@identity id';
}

my $rs = query_select($lastInsertIdSQL);
return $rs->fetchrow_hashref->{'id'};
}

sub openDatabase(){
return DBI->connect($dbstring, $user, $pass,
{RaiseError => 1, PrintError => 1});

...and they given me this to add but i don't know where to add, my MySQL is an address: castleoffrance.ipowermysql.com and user is cdef database name is db so i should add this somewhere to what is given also?

$db_connection = mysql_connect ($dbhost,$dbusername,$dbpassword) or die("Could not connect to DB");
mysql_select_db ($database) or die("Could not find DB");

anyone can help, tkz...