Module Pool Prgramm update

HI Guru's,

Iam new to ABAP..copy the standard abap module pool programm rggbs000 into ZGGBS000 include following code..

• Substitute FI line item text (BSEG-SGTXT) with corresponding

• purchase order item text(EKPO-TXZ01).

----

FORM u900.

TABLES: ekpo, makt.

CLEAR: ekpo-txz01.

IF bkpf-blart = 'WE'.

• Get PO Item Text for GR docs

SELECT SINGLE txz01 INTO ekpo-txz01

FROM ekpo

WHERE ebeln EQ bseg-ebeln

AND ebelp EQ bseg-ebelp.

IF sy-subrc EQ 0.

bseg-sgtxt = ekpo-txz01.

ENDIF.

• Get Material Master text for GI docs

ELSEIF bkpf-blart = 'WA'.

SELECT SINGLE MAKTX INTO makt-maktx

FROM makt

WHERE matnr = bseg-matnr

AND spras = 'EN'.

IF sy-subrc EQ 0.

bseg-sgtxt = makt-maktx.

ENDIF.

********************************************TMQ-S

CLEAR: ekpo-txz01.

ELSEIF bkpf-blart = 'RE' AND bseg-bschl = '31'.

• Get PO Item Text for IR docs

SELECT SINGLE txz01 INTO ekpo-txz01

FROM ekpo

WHERE ebeln EQ bseg-ebeln AND ebelp EQ bseg-ebelp.

• OR bschl EQ bseg-bschl = '31'.

IF sy-subrc EQ 0.

bseg-sgtxt = ekpo-txz01.

ENDIF.

*********************************************TMQ-E

ENDIF.

ENDFORM. "End of u900

with this code display the text bseg-sgtxt in one line item only...user requirement is to display text in all line items in FI documents how to do it.. any one can help me..

regards

JK