AT SELECTION-SCREEN ON VALUE-REQUEST FOR

Experts,

I have two selection parameters on Selection_Screen as subscreen, as below:

• Custom Selection Screen 1010

selection-screen begin of screen 1010 as subscreen.

SELECTION-SCREEN BEGIN OF BLOCK b2 WITH FRAME TITLE text-001.

SELECT-OPTIONS :

s_matnr FOR mara-matnr MODIF ID sc1, "Material

s_grid FOR mara-J_3APGNR MODIF ID sc6, "Grid values "pkb001

SELECTION-SCREEN END OF BLOCK b2.

selection-screen end of screen 1010.

Now i want to populate s_grid (Grid value) based on the values enterd for s_matnr (material ).

but when i want use:

AT SELECTION-SCREEN ON VALUE-REQUEST FOR s_grid,

I'm not getting the values eneterd in s_matnr..

is the problem beacuse of subcreen?

Answers are highly appriciated.

Thanks.