select counter, emp_short, trans_date, debit, credit,
      (select sum(coalesce(debit,0) - coalesce(credit,0))
      from trans02 tr2
      where tr2.counter <= tr1.counter and 
            tr2.emp_short = tr1.emp_short) as 'Running balance'
from trans02 tr1
order by emp_short, counter;
go