Well, I could imagine it this way:
An user offers something in the "I got something to sell" forum and anther member becomes the highest bidder. A random key is generated and sent out to the bidder after the transaction is completed. (The one offering has to click on "Item sold" or something like that) The ransom key is part of a "Rate this user" link that gets sent out to the bidder as soon as he confirms the transaction on the board.
Is that what you need?
|