I have been asked to setup a new chat room and make the
history of conversations available to any member of the room by his or her
request. To point it clear, in a 3 user chat room, users A and B chat in
the morning and then leave the room. When user C enters the room later, he
should be able to read what the others were chatting before.
Can this be done? I've playing with the button 'read history' inside the
chat room but the list is always empty.

Thanks in advance.