Meaning of logic

Hai all,

Can somebody please explain me the meaning of the logic of this code?

• Pickup clearing document into internal table.

SELECT * FROM BSEG INTO TABLE ZCLEAR_DOC

WHERE BUKRS = FS_DTFIAR_3-BUKRS

AND BELNR = FS_DTFIAR_3-AUGBL

AND GJAHR = ZFISYEAR.

• Calculate amount to clear by looking for residual items.

• Find original invoice: Invoice reference or current item.

if FS_DTFIAR_3-REBZG = ''.

DOC_TO_LOOK = FS_DTFIAR_3-BELNR.

else.

DOC_TO_LOOK = FS_DTFIAR_3-REBZG.

endif.

Thank you.

Message was edited by: Visu Venkat