Using fckeditor 2.6.4.1 on different sub-domains

I have a domain on which I have several sub-domains and I'd like to use fckeditor 2.6.4.1 on the sub-domains. I put it on one and it works fine, but I can't get it to work on the other sub-domains.

I've installed the program on the other sub-domains just as I did on the first, but I either get a message saying the website is not there (where the editor should appear), or I get the actual website of the first domain I installed fckeditor on (where the editor should appear).

I'm using the php version.

On the page where I am wanting to use the editor I have this at the top of the page:

include($_SERVER['DOCUMENT_ROOT']."/fckeditor/fckeditor.php");

I've tried this with no success, as I am using the editor in forms located in a directory that is just above root and the fckeditor directory is also just above root:

include('./../fckeditor/fckeditor.php');

Further down the page on the form where my textarea would be I have this:

// $there = $_SERVER['DOCUMENT_ROOT'].'/fckeditor/';
$location = 'http://www.mysite.com/fckeditor/';

$oFCKeditor->BasePath = $location ;
$oFCKeditor = new FCKeditor('content') ;
$oFCKeditor->Value = '' ;
$oFCKeditor->Create() ;

I tried using server document root first since that worked on the first sub-domain, but didn't seem to work here so I just used the http.

Can you use fckeditor only once anywhere on a domain?