Open dataset - return code 8 - msg - Permission Denied

Question

This is the first time this company has tried to write files to the application server. They are running under Windows. The network admin set up a folder and I am getting a return code of 8 on 'open dataset'.  When I use this function to get more information I am getting
a run-time error that the ABAP is bad.
What is wrong with this function call?
pfilename =
saberdev\blacksmith\ftpout\bsproduct.txt
call function 'AUTHORITY_CHECK_DATASET'
EXPORTING
program = 'ZBS_PRODUCT_OUTBOUND_INTERFACE'
activity = 'WRITE'
filename = pfilename
EXCEPTIONS
no_authority = 1
activity_unknown = 2
others = 3.

Answer 1

Thanks, Santosh, that helped.
Now I am getting sy-subrc =  0 on the function call but I am still getting a return code of 8 on the open dataset.  Here is my code.
HELP!!
   call function 'AUTHORITY_CHECK_DATASET'
         EXPORTING
              program          = 'ZBS_PRODUCT_OUTBOUND_INTERFACE'
              activity         = 'WRITE'
         filename         = '
saberdev\blacksmith\ftpout\bsproduct.txt'
         EXCEPTIONS
              no_authority     = 1
              activity_unknown = 2
              others           = 3.
     check sy-subrc = 0.
    data: MSG(100).
    pfilename = '
saberdev\blacksmith\ftpout\bsproduct.txt'.
    CLEAR MSG.
    OPEN DATASET pfilename FOR OUTPUT IN TEXT MODE MESSAGE MSG.
    IF SY-SUBRC <> 0.
      CONCATENATE 'file error: ' MSG INTO MSG.
      MESSAGE E208(00) WITH MSG.
    ENDIF.