Developing a smartform... and I want to display the preview of the smartform automatically before i print without displaying the "print dialog box

For ONLY PREVIEW
ST_CONTROL_PARAMETERS-NO_DIALOG = 'X'.

ST_CONTROL_PARAMETERS-PREVIEW = 'X'.
For PRINTING DIRECTLY
ST_CONTROL_PARAMETERS-PREVIEW = ' '.

ST_CONTROL_PARAMETERS-NO_DIALOG = 'X'.

ST_OUTPUT_OPTIONS-TDIMMED = 'X'.

CALL FUNCTION v_fm_name

EXPORTING
ARCHIVE_INDEX =
ARCHIVE_INDEX_TAB =
ARCHIVE_PARAMETERS =
CONTROL_PARAMETERS = st_control_parameters
MAIL_APPL_OBJ =
MAIL_RECIPIENT =
MAIL_SENDER =
OUTPUT_OPTIONS = st_output_options
USER_SETTINGS = 'X'
IMPORTING

DOCUMENT_OUTPUT_INFO = st_document_output_info

JOB_OUTPUT_INFO = st_job_output_info

JOB_OUTPUT_OPTIONS = st_job_output_options

TABLES

IS_LABELS = IS_LABELS

EXCEPTIONS

FORMATTING_ERROR = 1

INTERNAL_ERROR = 2

SEND_ERROR = 3

USER_CANCELED = 4

OTHERS = 5.