Smartfrom print error

Question

THIS IS URGENT
when iam giving print preview iam able to get it but when iam giving the print iam getting error called 'ERROR IN GENERATING SMARTFORM'  this program is already exsisting . i made some changes in the smartfrom in positioning for some of  the windows. and after that iam not able get the print out
please help me, hope i will be getting the solution.
PRINT PROG.
DATA g_fmname TYPE rs38l_fnam.
SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE text-001.
PARAMETERS: p_vbeln TYPE vbrk-vbeln.
SELECTION-SCREEN END OF BLOCK b1.
START-OF-SELECTION.
  CALL FUNCTION 'SSF_FUNCTION_MODULE_NAME'
    EXPORTING
      formname           = 'ZSD_SMRTSALEINVOICE1'
    IMPORTING
      fm_name            = g_fmname
    EXCEPTIONS
      no_form            = 1
      no_function_module = 2
      OTHERS             = 3.
  IF sy-subrc <> 0.
    MESSAGE 'Error in opening the smartform'
            TYPE 'I'.
    LEAVE LIST-PROCESSING.
  ENDIF.
  CALL FUNCTION g_fmname
    EXPORTING
         s_vbeln  =  p_vbeln
    EXCEPTIONS
      formatting_error = 1
      internal_error   = 2
      send_error       = 3
      user_canceled    = 4
      OTHERS           = 5.
  IF sy-subrc <> 0.
    MESSAGE 'Error in generating the smartform'
            TYPE 'I'.
    LEAVE LIST-PROCESSING.
  ENDIF.
*these are the warnings iam getting inthe when i activate the smartform.*
@8R@     TOTAMT                 Field g_totinv has no defined value
@8R@     ROUNDEDVAL          Field G_DIFFV has no defined value
@8R@     TCSAMT                  Field G_SCRAP has no defined value
@8R@     INSURANCEAMT          Field G_INS has no defined value
@8R@     FREIGHTAMT          Field G_FREIGHT has no defined value
@8R@     OCTAMT               Field G_OCTRAI has no defined value
@8R@     VATAMT               Field G_VAT has no defined value
@8R@     SALESTAXAMOUNT          Field G_SALESTAX has no defined value
@8R@     SUBTOTAL_V          Field G_SUBTOT has no defined value
@8R@     DEVOLOPMENTCHARGES_V     Field G_DEVCHG has no defined value
@8R@     PACANDFARWORDINGAMT     Field G_PAC has no defined value
@8R@     DISCOUNTSVAL          Field g_disc has no defined value
@8R@     HRECSAMT          Field G_HRECESS has no defined value
@8R@     CESAMT               Field G_CES has no defined value
@8R@     CEDAMT               Field G_CED has no defined value
@8R@     AMOUNT               Field G_TOT has no defined value

Answer 1

Thanks for solution.
I actually commented the sy-subrc <> 0. line and again uncommented the line  and tried it and I got it. Well that answer is solved and iam getting the print out . but now the another big problem has arisen. The form has many fields some fields are coming into as per the bill document number but some fields are remaining same, for any bill document number these fields details coming same.
Please help me.