Debug SAPscript form

  CALL FUNCTION 'OPEN_FORM'
   EXPORTING
*     APPLICATION                       = 'TX'
*     ARCHIVE_INDEX                     =
*     ARCHIVE_PARAMS                    =
     DEVICE                            = 'PRINTER'
     DIALOG                            = 'X'
     FORM                              = 'Z_FORM_NAME'
     LANGUAGE                          = SY-LANGU
*     OPTIONS                           =
*     MAIL_SENDER                       =
*     MAIL_RECIPIENT                    =
*     MAIL_APPL_OBJECT                  =
*     RAW_DATA_INTERFACE                = '*'
*   IMPORTING
*     LANGUAGE                          =
*     NEW_ARCHIVE_PARAMS                =
*     RESULT                            =
   EXCEPTIONS
     CANCELED                          = 1
     DEVICE                            = 2
     FORM                              = 3
     OPTIONS                           = 4
     UNCLOSED                          = 5
     MAIL_OPTIONS                      = 6
     ARCHIVE_ERROR                     = 7
    INVALID_FAX_NUMBER                = 8
     MORE_PARAMS_NEEDED_IN_BATCH       = 9
     SPOOL_ERROR                       = 10
     CODEPAGE                          = 11
     OTHERS                            = 12.

    CALL FUNCTION 'START_FORM'
     EXPORTING
*   ARCHIVE_INDEX          =
       FORM                   = 'Z_FORM_NAME'
       LANGUAGE               = 'E'
       STARTPAGE              = 'SUMMARY'
*   PROGRAM                = ' '
*   MAIL_APPL_OBJECT       =
* IMPORTING
*   LANGUAGE               =
     EXCEPTIONS
       FORM                   = 1
       FORMAT                 = 2
       UNENDED                = 3
       UNOPENED               = 4
       UNUSED                 = 5
       SPOOL_ERROR            = 6
       CODEPAGE               = 7
       OTHERS                 = 8          .

    CALL FUNCTION 'WRITE_FORM'
     EXPORTING
       ELEMENT                        = 'SUMMARY_TOP'
       FUNCTION                       = 'SET'
       TYPE                           = 'BODY'
       WINDOW                         = 'MAIN'
* IMPORTING
*   PENDING_LINES                  =
     EXCEPTIONS
       ELEMENT                        = 1
       FUNCTION                       = 2
       TYPE                           = 3
       UNOPENED                       = 4
       UNSTARTED                      = 5
       WINDOW                         = 6
       BAD_PAGEFORMAT_FOR_PRINT       = 7
       SPOOL_ERROR                    = 8
       CODEPAGE                       = 9
       OTHERS                         = 10.

    select * from zdatabasetab into wa_dbtab.
*     form would contain fields from wa_bdtab to be displayed
      CALL FUNCTION 'WRITE_FORM'
       EXPORTING
         ELEMENT                        = 'SUMMARY'
         FUNCTION                       = 'SET'
         TYPE                           = 'BODY'
         WINDOW                         = 'MAIN'
* IMPORTING
*   PENDING_LINES                  =
       EXCEPTIONS
         ELEMENT                        = 1
         FUNCTION                       = 2
         TYPE                           = 3
         UNOPENED                       = 4
         UNSTARTED                      = 5
         WINDOW                         = 6
         BAD_PAGEFORMAT_FOR_PRINT       = 7
         SPOOL_ERROR                    = 8
         CODEPAGE                       = 9
         OTHERS                         = 10.
    endselect.

    CALL FUNCTION 'END_FORM'
* IMPORTING
*   RESULT                         =
     EXCEPTIONS
       UNOPENED                       = 1
       BAD_PAGEFORMAT_FOR_PRINT       = 2
       SPOOL_ERROR                    = 3
       CODEPAGE                       = 4
       OTHERS                         = 5.

    CALL FUNCTION 'CLOSE_FORM'
*     IMPORTING
*       RESULT                         =
*       RDI_RESULT                     =
*     TABLES
*       OTFDATA                        =
     EXCEPTIONS
       UNOPENED                       = 1
       BAD_PAGEFORMAT_FOR_PRINT       = 2
       SEND_ERROR                     = 3
      SPOOL_ERROR                    = 4
       CODEPAGE                       = 5
       OTHERS                         = 6.