Newdate/ASP

I have a question - again.

As you might know, I am in the process of creating a forum (actually already done), but I need a little help with some extra features.

I want to be able to see if the threads is new for the person. The question is - how do I do that?

I believe that the best way to do it is to save a cookie on the clients computer (on in a database or whatever), and then combine all the threads with the date that cookie contains.
The problem is, how do I check if the date is newer than what he has stored?

I would think it should be done something like this:

---
lastvisit = request.cookies("lastvisit")
latestpost = objCon("lastpost")

if isnewer(lastvisit, latstpost) then
'not a new thread
else
'new thread
end if
---

However, all of us know that this doesn't work.
I recon that there is a function that allows me to check it like this, but I don't remember it!
Can someone help me?

Thanks in advance
¨~VCasper

PS: If you wanna see the forum I am talking about, go to secretsofwar.net, log in (or sign up) and got o features, and then to the new forums.