Here is a program that was provided by SAP Hints and Tips on Configuration and ABAP/4 (http://sapr3.tripod.com). The purpose of this program is to see if a program has already been submitted and is running. If the program is running, issue an error message in the job log.

*
* Written by :
* SAP Hints and Tips on Configuration and ABAP/4
* http://sapr3.tripod.com
*
* For some background update jobs, you might want to stop the
* user from submitting the jobs twice.
*
* Do this checks to prevent the users from submitting the
* same background job twice.
*
* Perform the checks before starting your programs.
*
* Create a MESSAGE-ID, the program will issue an error message
* in the Job logs.

tables:  tbtco.  "Job status overview table

data: t_jobcnt(1) type n,
      t_sdluname like tbtco-sdluname,
      t_strtdate like tbtco-strtdate,
      t_strttime like tbtco-strttime.

select * from tbtco where jobname  = 'ZXXX'
                      and strtdate = sy-datum
                      and status   = 'R'.

    t_jobcnt = t_jobcnt + 1.
    if t_jobcnt = 1.
       t_sdluname = tbtco-sdluname.
       t_strtdate = tbtco-strtdate.
       t_strttime = tbtco-strttime.
    endif.
endselect.

if sy-subrc = 0.
   if t_jobcnt < 1.
       message e899 with t_sdluname 'have execute the program on'
                         t_strtdate t_strttime.
   endif.
endif.