Synchronisation problem between windows (PHP and Javascript)

Hello,

I've got a problem with the pages I developped, written with both PHP and
JavaScript.
My Web site is an ASP controlling an application :
In fact the Page1.php controls the application (application.exe) located on
the Server, and the Page 2.php reads the result of a log file
(application.log) generated by application.exe.
What I need to do is to read, in real-time, "application.log",
application.log still growing after application.log has been launched.

My problem is that when I launch the Page2 from a new session of a navigator
(IE for example), my devloppement works fine : Page2 reads in real time
application.log, but if I launche the Page2 from Page1 (with javascript
function such as window.open( "page2.php", ...)) page2.php begins to scroll
after the application.exe has ended, the process seems to be synchron (this
is just that i don't want).

So my problem is how to launch page2.php from page1.php in asynchonous
mode...?

Thanks for your help.

Chris.