Session Expired in popup

Question

Hi all,

I have a button that generates reports from a database via reportviewer.  This report is displayed in a popup.

 window.open(url, title, 'width=680,height=700,toolbar=no,location=no,status=0,scrollbars=0');

The issue I'm trying to deal with is that if the user leaves this window open, logs off of my site, logs back on and tries to generate a report again, they get an ASP session expired error.  Since this is after a logoff, obviously, I can't preserve any javascript references to check if a page is open.  The closest that I've come to a solution is opening a black page with the same title, closing it, and then opening the report.

         var a = window.open('', title);
        a.close();
        window.open(url, title, 'width=680,height=700,toolbar=no,location=no,status=0,scrollbars=0');

This will close any open windows with that same title, but if there is no open window with that title, it will still open a new window briefly and then close it.  This can be rather annoying so I would prefer a different solution.  Is there some way to tell if a window with that title is already open without actually opening a new window, or is there a better way to accomplish what I'm trying to do?

Thanks