Chat PHP Fix

i have a bug in a php chatroom (+javascript) .. the chatroom is at [login to view URL] username:anything pass: (no password) the problem is: the only problem in this is the "private chat" (when u chat 1 on 1 ) ... the problem is the following.. if i send a private msg to someone , he get a pop up , and he can answer me and everything is ok .. but if 1 of us close the private window page , if the 2nd person re-message , i dont get a new pop up ! all the messages will be ignored!. if someone close and the 2nd person re-talk , it must re pop up the private window. Budget is maximun of 40 dollars. PLEASE BID ONLY AFTER CHECKING THE PROBLEM AND IF U CAN FIX IT IN A FEW HOURS I will provide you with ftp access to the folder, and I need it asap. This must be easy for someone experienced. I need it for today. Please before your bid message write the word "chat" to check if you read this description. URGENT!!! Please, the first that bid, if send PM quickly and I know he has time, he will get the job and an excellent review.