Sp transaction notification to control docdate

Question

Hi,
i've  this problem.  i've  Sales  Invoceis  ( OINV)  and  Credit  Notes (ORIN)  with  the  same  series
i  want  to  control,  by  sp  transaction  notification,  that  the user does   not  insert,  for  this  series, a  new  document  with  a  docdate  <  then  the  last  date  insert  about   OINV  or  ORIN   ( because  these  have  the  same  series)
i've  create  this  procedure:  but  i'm  not  able   to  control  docdate  about  OINV  and  ORIN together
DECLARE @GroupCode SMALLINT
     DECLARE @DocDate DATETIME
     DECLARE @MaxDocDate DATETIME
     DECLARE @Series INT
     DECLARE @NumAtCard NVARCHAR(100)
     DECLARE @Conta INT
     DECLARE @CardCode NVARCHAR(15)
    DECLARE @IdUtente SMALLINT
--     ADD     YOUR     CODE     HERE
-- Select the return values
IF @object_type = '13' AND @transaction_type = 'A'
          BEGIN
               SELECT @Series = OINV.Series,   @DocDate = DocDate
               FROM OINV   WHERE OINV.DocEntry = @list_of_cols_val_tab_del 
               BEGIN
                    /* 1. inserendo una fattura di vendita la data non deve essere precedente
                           a quella dell'ultima fattura per la stessa serie */
                    --Reperisco la serie a cui il documento appartiene
                    SELECT @MaxDocDate =   MAX(@DocDate)
                    FROM OINV
                    WHERE OINV.Series = @Series AND OINV.ObjType = @object_type
                    IF @DocDate < @MaxDocDate
                    BEGIN
                         SELECT @error = 1002,
                         @error_message = 'La data del documento non può essere precedente a quella dell''ultimo inserito ' + CONVERT(VARCHAR, @MaxDocDate, 103)
                    END

Answer 1

Hi,
Correct this
SELECT @MaxDocDate = MAX(@DocDate)
FROM OINV
WHERE OINV.Series = @Series AND OINV.ObjType = @object_type
to
SELECT @MaxDocDate = MAX(DocDate)
FROM OINV
WHERE OINV.Series = @Series AND OINV.ObjType = @object_type
Thanks
Malhaar