Reloading page from embedded applet disables session

[Sam Seaver]

Dear all,
I have an embedded applet that does a lot of funky stuff before reloading the very page it resides in:
getAppletContext().showDocument(new URL(www.same-page.com?id="longnumber"));
This disables the applet, and executes some other JSP code, including changing some session parameters. I want to be able to press the back button to restart the applet, albeit WITH the changes in the session, but it doesnt work.
Am I right in thinking that by calling the new URL from the applet, I'm actually starting a new session, and pressing 'back' goes back to the old one?
Whats happening?
thanks
Sam