not able to change error msg to warning msg which in PO check include

Hi Expert ,

I made a change in a include with po creation for a specific order type , condition is when eheck error message of PO the msg should be change error to warning . but itz not shown as a warning W but itz shows error when we declare it as E , at the time of PO check.

code is -

LOOP AT tekpo.

SELECT matnr ekgrp werks FROM marc INTO CORRESPONDING FIELDS OF TABLE it_wint WHERE matnr = tekpo-matnr

AND werks = tekpo-werks.

READ TABLE it_wint WITH KEY matnr = tekpo-matnr .

IF tekpo-matnr <> space.

IF it_wint-ekgrp <> i_ekko-ekgrp .

if i_ekko-bsart <> 'BTD' and i_ekko-bsart <> 'BTO' .

MESSAGE E037(zs) WITH tekpo-matnr i_ekko-ekgrp.

ELSE.

MESSAGE W037(zs) WITH tekpo-matnr i_ekko-ekgrp .

ENDIF.

ENDIF.

ENDIF.

CLEAR it_wint.

ENDLOOP.