ABAP program for find the user-exits of a SAP transaction code

report zuserexit no standard page heading.
tables : tstc, tadir, modsapt, modact, trdir, tfdir, enlfdir.
         tables : tstct.
data : jtab like tadir occurs 0 with header line.
data : field1(30).
data : v_devclass like tadir-devclass.
parameters : p_tcode like tstc-tcode obligatory.

select single * from tstc where tcode eq p_tcode.
if sy-subrc eq 0.
   select single * from tadir where pgmid = 'R3TR'
                    and object = 'PROG'
                    and obj_name = tstc-pgmna.
   move : tadir-devclass to v_devclass.
      if sy-subrc ne 0.
         select single * from trdir where name = tstc-pgmna.
         if trdir-subc eq 'F'.
            select single * from tfdir where pname = tstc-pgmna.
            select single * from enlfdir where funcname =
            tfdir-funcname.
            select single * from tadir where pgmid = 'R3TR'
                               and object = 'FUGR'
                               and obj_name eq enlfdir-area.

            move : tadir-devclass to v_devclass.
          endif.
       endif.
       select * from tadir into table jtab
                     where pgmid = 'R3TR'
                       and object = 'SMOD'
                       and devclass = v_devclass.
        select single * from tstct where sprsl eq sy-langu and
                                         tcode eq p_tcode.
        format color col_positive intensified off.
        write:/(19) 'Transaction Code - ',
             20(20) p_tcode,
             45(50) tstct-ttext.
                    skip.
        if not jtab[] is initial.
           write:/(95) sy-uline.
           format color col_heading intensified on.
           write:/1 sy-vline,
                  2 'Exit Name',
                 21 sy-vline ,
                 22 'Description',
                 95 sy-vline.
           write:/(95) sy-uline.
           loop at jtab.
              select single * from modsapt
                     where sprsl = sy-langu and
                            name = jtab-obj_name.
                   format color col_normal intensified off.
                   write:/1 sy-vline,
                          2 jtab-obj_name hotspot on,
                         21 sy-vline ,
                         22 modsapt-modtext,
                         95 sy-vline.
           endloop.
           write:/(95) sy-uline.
           describe table jtab.
           skip.
           format color col_total intensified on.
           write:/ 'No of Exits:' , sy-tfill.
        else.
           format color col_negative intensified on.
           write:/(95) 'No User Exit exists'.
        endif.
      else.
          format color col_negative intensified on.
          write:/(95) 'Transaction Code Does Not Exist'.
      endif.

at line-selection.
   get cursor field field1.
   check field1(4) eq 'JTAB'.
   set parameter id 'MON' field sy-lisel+1(10).
   call transaction 'SMOD' and skip first   screen.

*---End of Program