BDC_Scrolling_Code_Check

Hi..

I am showing you the following piece of code whic one of my peers has written but I am unable to understand the scrolloing part :-

LOOP AT vit_ekpo1 WHERE ebeln = lit_lips-vgbel.

l_line_no = l_line_no + 1.

IF vit_ekpo1-ebelp = lit_lips-vgpos.

vit_ekpo1-flag = 'X'.

MODIFY vit_ekpo1 TRANSPORTING flag.

EXIT.

ENDIF.

ENDLOOP.

l_cno = l_line_no.

• Calculation for table controller

CONCATENATE 'LIPSD-G_LFIMG(0' l_cno ')' INTO l_fname.

WRITE lit_lips-lfimg TO l_lfimg UNIT lit_lips-meins.

• For scrolling the table control

IF l_line_no > 3.

PERFORM sub_bdcfill USING :

space space space 'BDC_OKCODE' '=POPO_T',

'SAPMV50A' '0111' 'X' space space,

space space space 'RV50A-POSNR' l_cno,

space space space 'BDC_OKCODE' '=WEIT',

'SAPMV50A' '1000' 'X' space space.

MOVE 'LIPSD-G_LFIMG(01)' TO l_fname.

ENDIF.

I want to know what exactly does '=POPO_T' and '=WEIT' do and what is the logic behind seeting the condition > 3.

Any guesses are also welcome.

Thanks