problem with internal table initialisation in EBP system

Hi

I work in EBP system, and i made a specific work in LBBP_POCF0o program. It is in the displaying items of a purchase order.

This is what i done:

LOOP AT t_screen_items WHERE del_ind NE 'X'.

w_old_total = w_old_total + t_screen_items-value.

CLEAR:t_screen_items.

ENDLOOP.

loop at gt_item where del_ind ne 'X'.

w_new_total = w_new_total +

( gt_item-GROSS_PRICE * gt_item-quantity ).

clear: gt_item.

endloop.

if w_new_total GT w_old_total.

MESSAGE I001(ZBBP_PO) WITH

'elle possède un montant supérieur'

' à celui déterminé intialement.'

'Veuillez modifier la commande.'.

MOVE 'X' TO w_checksum_flag.

endif.

My problem is that if i use the elevator at the screen, the system is looping only at the first element visible on the screen, so the "LOOP AT t_screen_items" is wrong. i don't understand why the sytem doesn't count all the elements of the internal table t_screen_items...

Thank you for your help.