php message board system

[apm]

What i am lookign ofr a is a simple message board system.

This is for a reverse auction site. So if the buyer wants to send a message to the seller for aprticulr auction he can. The seller can only send a message to the buyer if the buyer has snet the message first.

Each auction of each buyer has a seperate thread. And within that thread there coudl be multiple messages to each seller, whihc should be grouped to gather.

I think i am being a bit confusing. Basically.

AUCTION1 MESSAGE THREAD

sent: buyer1
reply: seller1
sent: buyer1
reply: seller1
sent: buyer1
reply: seller1

sent: buyer1
reply: seller2
sent: buyer1
reply: seller2

AUCTION2 Thread

sent: buyer1
reply: seller2
sent: buyer1
reply: seller2

sent: buyer1
reply: seller4
sent: buyer1
reply: seller4

I hope that helped.

Is there a system avalible that can do this using mysql and php4. SOmethign that can achive this very simply. And uses my design templates.

Thanks
apoorva