title: In javascript, how can I uniquely identify one browser window from another which are under the same cookiedbased sessionId
body: <p>The users of my web application may have more than one browser window open and pointed to the same page.  I would like the state of certain things in the page (loaded via ajax) to be retained across postbacks.  I can either store in a cookie or on my server.  Either way, I can't think of how I can distinguish each window.</p>
  
  <p>For example, say user Bob has two browser windows open to the ListOfSomething page.  Each list has a <em>LoadedPageNumber</em> attribute which I need to persist.  Otherwise users always end up on page 1 when they refresh.  Bob might have loaded browser window 1 and pointed it to page 5 and then loaded browser window 2 and pointed it to page 14.  If I just store the attribute based on session id, Bob will get page 14 in window 1 if he refreshes it.</p>
  
  <p>Note that my state variables are actually much more complex than this simple example and my inability to persist them could lead to big problems (weaknesses in my app).</p>
  
  <p>I need some kind of browser window id or something.  It of course needs to be a cross-browser solution (IE6+, Wekbit?+, FF2+)</p>
  
  <p>Any ideas?</p>
  
  <p>Note on relevance:  Keep in mind that this is useful also for the case where you're mixing older forms based pages with newer AJAX enabled items.  Sometimes you need to postback the forms and you don't want to loose some client side state values.</p>