Once request to the "/stop-the-server/helper-stop-httpd.exe" resource is performed, SAWS will continue to serve content for additional 5 seconds (to allow the resource to refer to any other content like scripts, stylesheets, images or even multimedia), and then SAWS will terminate, attempting to eject CDROM if it was started from CDROM. Browser window won't be closed.
It's possible to implement a HTML button (i.e a HTML FORM with a single BUTTON or SUBMIT) that triggers POST request to the url "/stop-the-server/helper-stop-httpd.exe" too. In fact, POST request is more preferred than simple <A HREF="/stop-the-server/helper-stop-httpd.exe"> because browser will not even think about caching results (and if results are cached, the SAWS won't be stopped). If you are implementing STOP functionality via link (instead of a button), use random value as GET argument of the URL, i.e. instead of
<A HREF="/stop-the-server/helper-stop-httpd.exe">use
<A HREF="/stop-the-server/helper-stop-httpd.exe?anyname=<?php print rand() ?>">
If you configured your project to use Portable Firefox as the browser, you can intruct Webserver for CD to stop automatically once all windows of Portable Firefox are closed, by checking corresponding checkbox in the CDBuilder. Don't forget that there are two checkboxes - in configuration of browser for Windows, and in configuration of browser for Mac OS X.