I got message error please tell me that what is it.
ERRORESS-SETVALUE -> error in sqlcommand[insert into session(
session_id.app_id.value.register_date,expire_date, lastmod_date,in_used) values('1F454FFEC288206F8B18B1CBB85C8E2A',1,'_sess ion_app_id=733a313a2245622b],'Mar 17 2003 14:19:44','Mar 17 2003 15:04:44','Mar 17 2003 14:19:44',0)] - (Sybase message:You server command (family id #0,process id #25) was deadlocked with another process and has been chosen as deadlocked victim .Re-run your command (severity 13)

*** In my Database don't have session table . I am not sure the session is system table or user table please answer me thank you*****

the server has detected to deadlock situation and therefore choose one of the transactions as victim after a defined timeslize.
rerun the statement.

p.s. possibly you should choose row level locking for the specific table to prevent deadlocks in the future or minimize them