use schedule to backup a database on maxDB76

hello, I want to use schedule to backup  a  database on maxDB76 
first, backup can success if I use only the dbmcli command :

to begin with , I define a file (backup.dbmcli) , write the dbmcli commands 
in the file;

    db_online
    medium_put CompleteBak CompleteBak_COM File DATA 0 0 YES
    util_connect
    backup_start CompleteBak  DATA  AUTOIGNORE
    util_release

next, call the script:

dbmcli -d hoteldb -u dbm,dbm -i backup.dbmcli

backup can be successful.


then I want to use schedule to backup.
to begin with , I define a file (schedulebackup.dbmcli) , write the dbmcli 
commands 
in the file;

    scheduler_start
    scheduler_create_job 11:15:00 "db_online"
    scheduler_activate_job 0
    scheduler_create_job 0 "medium_put CompleteBak CompleteBak_COM File DATA 0 
0 YES"
    scheduler_activate_job 1
    scheduler_create_job 1 "util_connect"
    scheduler_activate_job 2
    scheduler_create_job 2 "backup_start CompleteBak  DATA  AUTOIGNORE"
    scheduler_activate_job 3
    scheduler_create_job 3 "util_release"
    scheduler_activate_job 4


next, call the script:

dbmcli -d hoteldb -u dbm,dbm -i schedulebackup.dbmcli  

when execute to command : scheduler_create_job 2 "backup_start CompleteBak  
DATA  AUTOIGNORE"

the schedule execution result is:

ID 3
owner: dbm
status: inactive
runs: after 2
last run: 2005-04-06 11:15:13
          DBM Server PID 3128
          return code ERR (-24992)
dbm_command:  backup_start CompleteBak  DATA  AUTOIGNORE          

ERR (-24992) means: ERR_NOUTILSESSION: no utility session available
  
My question  is that the backup can success if I use only the dbmcli command  .
but it fails  to use schedule to bakup ,why ?
 
thanks.

2005.4.6