Visited Forum Cookie

[morningstar]

Hello i got a question about displaying new pictures on new posts since last visit.

I was wondering if someone visit the site you got the lastvisit date. But as soon as someone visit the site the lastvisit date is updated to the current date - time.

So that means he can view one thread and then all threads will be marked as read. The you could make another cookie with an array of all visited threads.
So you got 2 cookies, 1 with last visit and 1 with all threadid's visited since last date.

I was thinking this way:
1 = someone visit the site you get the lastvisit
2 = you make a cookie with all threadids that will be visited.
3 = you update the new last visited date
4 = every time someone visit a thread you add the thread to the threadid cookie
5 = you check cookie at step 4 and see which threads are new and which not

but if someone return to the forum home again, the last visit will be updated again, something that shouldnt be done.
Could someone please help me out?

[justsomeone]

you could just use a "last visited" date for each forum.

Each date could be stored in a cookie.

Or you could just store a userid in a cookie and use a database to store a last visited date for each forum for each userid.