How to filter appropriate messages

Hi, I am currently using a packet collector but everytime i log on , i receive every single message in that is in the collector everytime i do collector.pollResult. I.e if someone sent A B C , when i go to a muc room again, I will get A B C and if I rejoin i still get A B C, there are no timestamp on the messages so I cannot filter them according to the time i logged in. i.e If the message is older than the login time then do not send it back to me. Is there anyway to filter only the latest message ?

Ah i was just found out the setting in openfire. Just set the room history setting to 0.