best way to access/create SITE_ROOT and SERVER_ROOT values in PHP?

[pneuttofe]

I need 2 different paths, one for includes and one for js/css etc. I'm using \[code\]mod_rewrite\[/code\]. The below works fine....Currently all my files contain this at the top\[code\]define('SERVER_ROOT', 'C:/wamp/www/site_folder/');define('SITE_ROOT', 'http://localhost/site_folder/');\[/code\]and then files are called like so:\[code\]require_once SERVER_ROOT . 'st_wd_assets/inc/func_st_wd.php'; <link rel="stylesheet" type="text/css" href="http://stackoverflow.com/questions/2963997/<?php echo SITE_ROOT;?>st_pages/user_area/css/user_area.css" media="screen"/>\[/code\]as you can probably see, it's going to be a massive chore to update the top of every file everytime i move versions between the localhost and my live server.What's the best/standard way of defining these ROOT values?I can't see a solution in the \[code\]$_SERVER\[/code\] super global? Do people normally just use VirtualHosts? But then wouldn't it still be necessary to define ROOT constants?