some kind of redirection (not the header function)

Hi!!! I´m programming a site in PHP, where I want to do the following: I will have a set of different directories, where each directory must execute the same PHP pages, but giving as result different data, according to the directory where you are located (obtained by $_SERVER[´PHP_SELF´] for example). For example I have: http://www.domain.com/directoryA/ http://www.doamin.com/directoryB/ So each one must have (or should act as if they had) the same PHP pages and directories under them. The solution I thought, as copying each page in every directory makes no sense (if I modify the code I´ll have to change all the pages in all directories), is to have an includes directory. where I put all the PHP pages, and in each of the different directories I create pages that simply include or require the ones from the include directories. That way I´ll only modify code inone place.. Now.. is there any better way to achieve this?? I thought that maybe with some Apache stuff, but I don´t think thereś something that will help, since directives such as RedirectMatch, etc. rewrite the URL, and I don´t want that, I want the URL to remain http://www.domain.com/directoryX/whatever.php Is there any way to do this, or I should stick up with the includes?? Thnx in advance, Juan