The most common approach I have come across is to track each time someone
requests a page and record it in a db. Any entries less than 20 mins old
(for default time-out settings) are considered 'live'. That is, if you can
just accept that you are potentially 20 minutes out-of-date when you query
the DB, life is a lot easier.
As Pete has stated, there is currently no guarranteed way of tracking your
users accurately.
I'm not sure if this is helpful to you... Why are you trying to track the
length of time they are on your site? Is it for billing for a provided
service? Or just for your information?
If it just informational, then my method may well be OK. If you need to be
more accurate, I think you will be disappointed..
hth
Chris
"Pete" <an*******@devdex.com> wrote in message
news:Ow**************@TK2MSFTNGP10.phx.gbl...
You could trap this *sometimes* by writing some javascript in your
pages, trapping the onBeforeUnload event and maybe posting something to
your server then.
But there are ways the user can get past this, e.g. physically bringing
down the connection before they close the browser (disconnecting the
phone line if its a dialup connection), or even (a bit extreme!) just
switching the machine off at the wall without exiting anything.
I'm fairly sure there is no 100% reliable way to achieve what you want.
You can only really record when the user comes back to your site.
HTH,
Pete
*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!