Formatted Search to imput TaxGroup Automatically when create a new item

Question

I create a FMS to imput the taxgroup when create a new item. But when execute the FMS this show a list  of values. Whats a problem?
declare @iva5 VARCHAR(10)
declare @iva12 VARCHAR(10)
declare @iva21 VARCHAR(10)
set @iva5='D1'
set @iva12='D2'
set @iva21='D3'
SELECT CASE
WHEN T0.ITMSGRPCOD IN ('107','108','109','110','111','116') THEN @iva21
WHEN T0.ITMSGRPCOD IN ('112','113','114','115') THEN @iva12
WHEN T0.ITMSGRPCOD IN ('105','106') THEN @iva12
ELSE @iva12 END
FROM OITM T0

Answer 1

You should refer to the actual item's item group value:
declare @iva5 VARCHAR(10)
declare @iva12 VARCHAR(10)
declare @iva21 VARCHAR(10)
set @iva5='D1'
set @iva12='D2'
set @iva21='D3'
SELECT CASE
WHEN $[OITM.ITMSGRPCOD] IN ('107','108','109','110','111','116') THEN @iva21
WHEN $[OITM.ITMSGRPCOD] IN ('112','113','114','115') THEN @iva12
WHEN $[OITM.ITMSGRPCOD] IN ('105','106') THEN @iva12
ELSE @iva12 END