Ok here is my scalar UDF

CREATE FUNCTION fn_getjudge(@module char(10), @keyident nvarchar (12))
RETURNS char(3)
begin
DECLARE @judgecode Char(3)
SET @judgecode=''
if @module='MV'
SELECT @judgecode= mv_judge FROM motorvehicle
WHERE keyident = @keyident
RETURN (@judgecode)
if @module='LL'
SELECT @judgecode= ll_judge FROM locallaw
WHERE keyident = @keyident
RETURN (@judgecode)
if @module='CV'
SELECT @judgecode=civ_judge FROM civil
WHERE keyident = @keyident
RETURN (@judgecode)
if @module='CRM'
SELECT @judgecode=crm_judge FROM criminal
WHERE keyident = @keyident
RETURN (@judgecode)
if @module='SC'
SELECT @judgecode=sc_judge FROM smallclaims
WHERE keyident = @keyident
RETURN (@judgecode)
end