SQL info: MySQL Query Error

Time: 2009-1-9 2:38am
Script: /hotel.php

SQL: INSERT INTO t_session (sid,uid,islogin,isadmin, updated, sessiondata ) VALUES ('ae0156','','','', '1231439930', 'a:0:{}')
Error: Duplicate entry 'ae0156' for key 1
Errno.: 1062