sub connectdb {
    my ($data_source, $database, $user_id, $passwd ) = 
        qw( server_hostname_or_IP database_instance username password );
    my $conn_string = "driver={SQL Server};Server=$data_source;Database=$database;UID=$user_id;PWD=$passwd";
    my $dbh = DBI->connect( "DBI:ODBC:$conn_string" ) or die $DBI::errstr;
    return $dbh;
}