Running a Job

I am unable to run a job based on a simple example given by oracle PL/SQL programming book.  My DBscripts are as follows; It need to activate a procedure "log_proc12" which only insert the sysdate into a field.  There is no problem with my prcedure as it works by itself.  I can desc the job, but it' don't call by itself.  Could it be the JOB_QUEUE_PROCESS is set to zero?  Can showone tell me where the file INIT.ORA is usually located in the UNIX machine if that is the cause.  Thanks


Set Serveroutput on
Declare
      Job_Num INTEGER;
Begin
      DBMS_JOB.SUBMIT(
                  Job_Num,
                  'log_proc12;', SYSDATE,
                  'SYSDATE + (10/(24*60*60))');
      DBMS_Output.put_line('Job Number = '||To_char(Job_Num));
      Exception
            When others then
                  DBMS_Output.put_line(SQLERRM);
End;
/