Ok I created a funtion that works when I execute it as
"select * from fn_judgecode('_1KD0WC86U')" from the SQL Query analyzer
and it returns mv_judge.

here is the function
CREATE FUNCTION fn_judgecode
(@keyident nvarchar (12))
RETURNS TABLE
AS
RETURN (
SELECT mv_judge
FROM motorvehicle
WHERE keyident = @keyident
)

but when I try to use the funtion as a column in a SQL select by executing
"select py_paydate, fn_judgecode('_1KD0WC86U') from payments"

I get an error "'fn_judgecode' is not a recognized function name."

Does anyone know what I am doing wrong ?

Thanks Again !