back-end and front-end separation

[eluser]dejitaru[/eluser]
When I work on my localhost I have this folders:
D:\proyects\proyect1\
-frontend
-backend
-system
-www
--index.php
--admin
---index.php

D:\proyects\proyect2\
-frontend
-backend
-system
-www
--index.php
--admin
---index.php
Then in the first index.php I have:
$system_folder = "../system";
$application_folder = "../frontend";

..And in admin/index.php I have:
$system_folder = "../../system";
$application_folder = "../../backend";

This way when I upload my files to the server I put frontend,backend and system outside the public_html and the contents of www goes into public_html