Unable to delete a file on application server

Question

Hello Experts,
I have gone through  couple of post and sample nothing worked that's the reason Iam posting a query here.
Please help me with your valuable suggestions.
I am reading a file from the application server running a BDC program to update my ztable all works fine.
now i wanted to move this file to another folder thats too working perfectly but now when i try deleting the older one it is not getting deleted.
I have closed the dataset and checked the authorization that is not a concern but still it is not getting deleted.
I have pasted the code below.
For READ and CLOSE dataset it returns subrc as 0 but after delete it returns 4.
data : mess type string.
OPEN DATASET ld_file FOR INPUT IN TEXT MODE ENCODING DEFAULT message mess.
IF SY-SUBRC = 0.
DO.
    READ DATASET ld_file INTO wa_string.
    if sy-subrc eq 0.
        append wa_string to it_string.
        clear wa_string.
    else.
        exit.
    endif.
  enddo.
  close dataset ld_file.
  delete dataset ld_file.
else.
WRITE 'Unable to open source file to move the content'.
endif.
Regards,
Ranjith N

Answer 1

Hello Mr Ghode,
Thaking you for your response on my query.
as you said to handle exception this is what i have done.
kindly verify the same would be of great help.
still iam unable to delete the file.  
OPEN DATASET ld_file FOR INPUT IN TEXT MODE ENCODING DEFAULT.
  IF SY-SUBRC = 0.
    DO.
      READ DATASET ld_file INTO wa_string.        "LV_LINE is variable to hold line contents being read
      if sy-subrc eq 0.
        append wa_string to it_string.
        clear wa_string.
      else.
        exit.
      endif.
  enddo.
  close dataset ld_file.
  if sy-subrc eq 0.
  try.
    delete dataset ld_file.
    catch CX_dynamic_check into t_ref.
    err_txt = t_ref->get_longtext( ).
endtry.
endif.
endif.
Regards,
Ranjith N