DECLARE  
XXTAX_JOB_LOG_ID  VARCHAR2(30);  
XXTAX_JOB_NAME           VARCHAR2(30);
BEGIN  
SELECT LOG_ID, JOB_NAME  INTO   XXTAX_JOB_LOG_ID , XXTAX_JOB_NAME FROM ALL_SCHEDULER_RUNNING_JOBS  WHERE  SESSION_ID = SYS_CONTEXT('USERENV','SID')  
  AND RUNNING_INSTANCE = SYS_CONTEXT('USERENV','INSTANCE');    
END;

I'm unsure what you're trying to do here. The query uses the current session ID, so only returns a row if you call it from within the job itself. i.e. you'll have to update the job action to include this.

Even if you do, it tells you relatively little. ALL_SCHEDULER_RUNNING_JOBS.LOG_ID holds the "SUCCEEDED" Log ID that will get created when the job completes. If you're trying to see what a job is doing NOW, it's of no use.

If you want to check the progress of active jobs, add logging to the code in the job itself. This will insert details of progress into a table. Logger is a good package to use if you don't already have something in place:

https://github.com/OraOpenSource/Logger

If this is not what you want, please clarify what you're trying to do.