[WHAT'S THIS - define('ROOT_DIR', realpath (dirname(__FILE__)));]

Hi Can anybody help me on this one ?

    I am trying to install a my space resource script and this one has got me stumped, I've been up way too late trying to figure it out  :-[

I'm stuck on this code in the config.php file:
the full path is /home/houseof/public_html/myspacestuff

URL is [url=http://www.houseofgar.net/myspacestuff]http://www.houseofgar.net/myspacestuff[/url]

I have been able to get the site up, limping, but it has many bugs and I think it may be the
way I have configured this syntax.

[code]define('ROOT_DIR',    realpath  (dirname(__FILE__)));
define('MP3FLASHLIST_DIR',ROOT_DIR."/uploads/playlist");[/code]
What do I do with this part: (dirname(__FILE__)));

Currently I have it configured like this:

[code]define('ROOT_DIR', '/home/houseof/public_html/myspacestuff/');
define('MP3FLASHLIST_DIR','/home/houseof/public_html/myspacestuff/uploads/playlist');[/code]
There is no formatting and the navigation return 404 errors, I am assuming it has something to do with the fact that I removed [code](dirname(__FILE__)))[/code]
Can anyone help !!
Thanks a lot I really appreciate it

here's the whole config file

[code]<?
// database param
define('DB_TYPE', 'mysql');
define('DB_SERVER', 'localhost');
define('DB_USER', 'root');
define('DB_PASSWORD', 'liumin');
define('DB_DATABASE', 'myspace');

// set
define('HOMEPAGE','http://myspace/');
define('SITENAME','Myspace Codes');
define('SHOWPIMP','ON'); //ON or OFF      show left-top

define('ROOT_DIR',    realpath  (dirname(__FILE__)));
define('MP3FLASHLIST_DIR',ROOT_DIR."/uploads/playlist");


$mysql_server = DB_SERVER;
$mysql_user = DB_USER;
$mysql_pass = DB_PASSWORD;
$mysql_db = DB_DATABASE;

$strDBServer = $mysql_server;
$strDBUser = $mysql_user;
$strDBPass = $mysql_pass;
$strDBName = $mysql_db;
$strPath = $site_url;

$site_name = SITENAME;
$site_url = HOMEPAGE;

$strFPID = "44824328";
$strFPName = "Sexy Me!!!!";
$strFPAge = "22";
$strFPQuote = "ADD ME!";
$strFPImage = "http://myspace-441.vo.llnwd.net/00389/14/43/389053441_m.jpg";
?>[/code]