ABAP Programming Help

I am writing a program using a table that is already in SAP. The table is VBAK and I'm trying to run an internal function "convert_to_local_currency" and I can't seem to get this to run correctly. There seems to be a problem with the loop statement, the convert function does not have conversion information for 'DEM' currency so there is an exception for that. The program initiates the sy-subrc = 5 and runs that output, but when the sy-subrc isn't 5 it should go onto the next output, however no conversions are ever done..

Below is the code that I've been working on I have commented out the loop and endloop statement.. can anyone offer me any help?? Thanks!

Jeff
(MIS Student)
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REPORT ZDCA10FINAL MESSAGE-ID ZD10 .

TYPES: TYP_vbak TYPE VBAK,
paymentsum type vbak-netwr,
CURRENCY TYPE VBAK-waerk.

DATA: WA_VBAK TYPE TYP_VBAK,
COLOR TYPE I VALUE 1,
LOCAL_AMOUNT TYPE VBAK-NETWR,
ivbak type standard table of typ_vbak,
CURRENCY TYPE VBAK-waerk.


*Array Fetch of the data into work area.
SELECT * FROM VBAK INTO WA_VBAK.

*Line colors.
IF color = 4.
color = 2.
ELSE.
color = 4.
ENDIF.

FORMAT COLOR = COLOR.

*LOOP AT IVBAK INTO WA_VBAK.

CALL FUNCTION 'CONVERT_TO_LOCAL_CURRENCY'

EXPORTING
DATE = SY-DATUM
FOREIGN_AMOUNT = WA_VBAK-NETWR
FOREIGN_CURRENCY = WA_VBAK-WAERK
LOCAL_CURRENCY = CURRENCY

IMPORTING
LOCAL_AMOUNT = LOCAL_AMOUNT

EXCEPTIONS
NO_RATE_FOUND = 5.

if sy-subrc = 5.
write: / WA_VBAK-ERNAM ,
15 WA_VBAK-AUDAT ,
30 WA_VBAK-NETWR,
60 wa_VBAK-WAERK,
80 local_amount color 6.

Else.

*Writing Output.
WRITE: / WA_VBAK-ERNAM ,
15 WA_VBAK-AUDAT ,
30 WA_VBAK-NETWR,
60 wa_VBAK-WAERK,
80 local_amount.

endif.

*endloop.

ENDSELECT.


CLEAR WA_VBAK-ERNAM.

*Error check.
IF SY-SUBRC <> 0.
MESSAGE i001.