Regarding Parameter statement in selection screen

Question

Hi All,
Pls provide me the logic for the below requirement.
The requirement is that in the selection screen if i give the input as 6months in paramenter option field,the employee data for the last six months sud be fetched in the report.And if i give 2 months ..the last 2months employee data sud be fetched by the report.
Pls help me how to proceed further.
Thanks,
Chakradhar.

Answer 1

Use logic like this..
data:
  begin of t_pernr occurs 0,
    pernr type pa0001-pernr,
  end of t_pernr.
parameters:
  p_period type i.
data:
  w_date type pa0001-begda,
  w_temp type i.
start-of-selection.
  if p_period lt 1
  or p_period gt 12.
    message 'Period must be between 1 and 12' type 'I'.
    exit.
  endif.
  w_date = sy-datum.
  w_date+6(2) = '01'.
  if w_date+4(2) gt p_period.
    w_date4(2) = w_date4(2) - p_period.
  else.
    w_temp = w_date+4(2) - p_period.
    w_temp = 12 + w_temp.
    w_date0(4) = w_date0(4) - 1.
    w_date+4(2) = w_temp.
  endif.
  select pernr
    from pa0001
    into table t_pernr
   where begda ge w_date.
   if sy-subrc eq 0.
   endif.