Get data in sap script

[#1]

Hello everyone,

I need to display MATNR from table VBAP in the table in main window of a sap script.
How do I do that?

This is what I tried:
in txt element i wrote

/:   PERFORM get_matnr IN PROGRAM ZGET_matnr
/:   USING &VBAP-MATNR&
/:   CHANGING &SIFRA&
/:   ENDPERFORM

and in my program I wrote this:

FORM get_matnr TABLES  itab  STRUCTURE itcsy
                             otab STRUCTURE itcsy.
DATA: sifra    TYPE vbap-matnr.

READ TABLE itab WITH KEY name = 'VBAP-MATNR' TRANSPORTING value.
sifra = itab-value.

 otab-value = sifra.
 MODIFY otab TRANSPORTING value WHERE name = 'SIFRA'.

But when I type &SIFRA& where I need my data to be displayed I dont get any values.
I also saw while debbuging that when I want to get some data from BSEG, I can do that, but from VBAP I cant.

Can anyone help I need a reply ASAP.
Thanks in advance.

[miske]

Any answer that helps would be highly appreciated. Please help.