Tcode = ME33K(Display contract agreement)

hi use belo fm

CALCULATE_TAX_ITEM

ex:

CLEAR LS_TAXCOM.
LS_TAXCOM-BUKRS = LS_EKKO-BUKRS.
LS_TAXCOM-BUDAT = LS_EKKO-AEDAT.
LS_TAXCOM-BLDAT = LS_EKKO-BEDAT.
LS_TAXCOM-WAERS = LS_EKKO-WAERS.
LS_TAXCOM-HWAER = LS_EKKO-WAERS.
LS_TAXCOM-KPOSN = LS_EKPO-EBELP.
LS_TAXCOM-MWSKZ = LS_EKPO-MWSKZ.
LS_TAXCOM-WRBTR = LS_EKPO-NETWR.
LS_TAXCOM-XMWST = 'X'.
LS_TAXCOM-SHKZG = 'H'.
LS_TAXCOM-TXJCD = LS_EKPO-TXJCD.
LS_TAXCOM-LIFNR = LS_EKKO-LIFNR.
LS_TAXCOM-EKORG = LS_EKKO-EKORG.
LS_TAXCOM-MATNR = LS_EKPO-MATNR.
LS_TAXCOM-WERKS = LS_EKPO-WERKS.
LS_TAXCOM-MATKL = LS_EKPO-MATKL.
LS_TAXCOM-MEINS = LS_EKPO-MEINS.
LS_TAXCOM-MGLME = LS_EKPO-MENGE.
LS_TAXCOM-MTART = LS_EKPO-MTART.
LS_TAXCOM-LAND1 = LS_EKKO-LANDS.
LS_TAXCOM-EBELN = LS_EKKO-EBELN.
LS_TAXCOM-EBELP = LS_EKPO-EBELP.
LS_TAXCOM-BWTAR = LS_EKPO-BWTAR.



REFRESH:LT_KOMV[].

CALL FUNCTION 'CALCULATE_TAX_ITEM'
EXPORTING
DIALOG = 'DIAKZ'
DISPLAY_ONLY = 'X'
I_TAXCOM = LS_TAXCOM
TABLES
T_XKOMV = LT_KOMV
EXCEPTIONS
MWSKZ_NOT_DEFINED = 1
MWSKZ_NOT_FOUND = 2
MWSKZ_NOT_VALID = 3
STEUERBETRAG_FALSCH = 4
COUNTRY_NOT_FOUND = 5
TXJCD_NOT_VALID = 6
OTHERS = 7.

LOOP AT LT_KOMV INTO LS_KOMV.

CASE LS_KOMV-KVSL1.
WHEN 'JII'.
LS_FINAL-IGST = LS_FINAL-IGST + ( ( LS_KOMV-KBETR / 1000 ) * LS_RSEG-WRBTR ).
WHEN 'JIC'.
LS_FINAL-CGST = LS_FINAL-CGST + ( ( LS_KOMV-KBETR / 1000 ) * LS_RSEG-WRBTR ).
WHEN 'JIS'.
LS_FINAL-SGST = LS_FINAL-SGST + ( ( LS_KOMV-KBETR / 1000 ) * LS_RSEG-WRBTR ).
WHEN 'JIM'.
LS_FINAL-IMGST = LS_FINAL-IMGST + ( ( LS_KOMV-KBETR / 1000 ) * LS_RSEG-WRBTR ).
ENDCASE.

ENDLOOP.

or if not work

use tables : bkpf and bseg.