smartform - parameters

Hi Friends

Iam using parameter option in select statement at my zprogram.

how can i pass this parameters value to smartform.

CALL FUNCTION v_form_name

EXPORTING

XMATNR = p_matnr

tables

itab = itab

EXCEPTIONS

FORMATTING_ERROR = 1

INTERNAL_ERROR = 2

SEND_ERROR = 3

USER_CANCELED = 4

OTHERS = 5.

IF sy-subrc <> 0.

MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

what r the steps needed in smartform...

i have declared the xmatnr in interface

but my output window display no records...

with regards

gowrishankar