send adobe form as email attachment issue

Hi ,

I want to send my generated custom Adobe form as email attachment, The driver program is copy of Standard SAP program RFKORDP1

Here ,after calling the Form FM , the parameter ls_formoutput-pdf is always blank

Please help me with a solution

CALL FUNCTION save_fm_name

    EXPORTING

      /1bcdwb/docparams = ls_docparams

      invoice           = gt_invoice

      oreciept          = gs_oreciept

      extra_details     = gt_extra_details                   

      one_time_addr     = gs_onetime                      

      s_expvat          = lr_expvat                            

      s_bldat           = lr_bldat                           

      s_budat           = lr_budat                            

      s_tcode           = lr_tcode                             

      s_usnam           = lr_usnam                             

      s_blart           = lr_blart                             

      bkpf_data         = gt_bkpf_data

      s_selvat          = lr_selvat

      s_selzero         = lr_selzero

      ch_mail           = ch_mail

    IMPORTING                                                   

      /bcwdb/formoutput = ls_formoutput                       

    EXCEPTIONS

      usage_error       = 1

      system_error      = 2

      internal_error    = 3

      OTHERS            = 4.

  IF sy-subrc <> 0.