Child window close / Parent Session problem

[Xing Rong]

I have an asp page to authenticate users by checking their
uid and password:

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If (request("UID") = "user" and request("Password") = "pwd") then
session("UID") = "user"
Session.Timeout= 300
End if
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For other ASP pages, I have

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if not IsUser() then response.redirect "Login.asp"

-- Here is the function
function IsUser ()
IsUser = False
if session("UID") = "user " then IsUser = True
End function
---------------------------------------

I also have a help link on each page. If you click the
link, a child window pops up using javascript.

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<a href="#" onClick="openWindow
('../Help/default.asp','','menubar=yes,scrollbars=yes,width= 600,height=400')">
---------------------------------------

<script language="JavaScript" type="text/JavaScript">

function openWindow (theURL,winName,features) {
window.open(theURL,winName,features);
}

</script>
---------------------------------------

Now, My problem is: I click the link, a pop-up child
window opened, I close the child window, back to the
parent page and refresh, it redirect me to the login page. Looks like
the session is terminated.

However, If I first login to my Yahoo email account and re-
do the above, no problems at all.

Is it strange? Anyone has any ideas?

Thanks!

[comettrouble]

I am having the same problem only with an aspx page. I my computer where i run tests using my local IIS the window.close does not cause any problems(session does not end).
But, when i put the page on the production server and click the window.close link on the popup window it ends the session.
The real strange thing is the page also closes using window.close after a
3 seconds if user not close window himself, but this does not cause the
session to end.
I've been looking around and you are the only one I could find with similar problem, which makes me think that it might be fixed through iis and some setting.
Just wondering if there is anyone else out there that has come up with this problem and if there is a solution to it.