Error in trigger while using insert

Hey there,

I'm new in using firebird, I'm trying to convert adatabase from MSSql to firebird. Now I have a error with a trigger,
SET TERM ^ ;

CREATE TRIGGER "TRIG_TIJDRG_LOGGING_BI" FOR "TIJDRG_LOGGING"
BEFORE INSERT
AS
DECLARE BARCODE VARCHAR(12);
DECLARE ORDERNR NUMERIC;
DECLARE BLADNR NUMERIC(15, 0);
BEGIN
IF(NEW."LOG_ID" IS NULL) THEN NEW."LOG_ID" = GEN_ID("GEN_TIJDRG_LOGGING_LOG_ID",1);
BARCODE=NEW.BARCODE;
IF (NEW.SCANNER <> 0 AND STRLEN(BARCODE)=11) THEN
BEGIN
IF (SUBSTRLEN(BARCODE,1,2) = '10') THEN
BEGIN
For Select ordernr,bladnr From Prodorder Where Paneelnr=(SUBSTRLEN(NEW.BARCODE,1,8) || ',' || SUBSTRLEN(NEW.BARCODE,9,3))
INTO ORDERNR,BLADNR
DO
BEGIN
Insert Into tijdrg_logging_ds (scanner,ordernr,bladnr,datum) VALUES (NEW.SCANNER,:ORDERNR,:BLADNR,NEW.DATUM);
END
END
END
END
^

COMMIT WORK ^
SET TERM ;^

Why is the INSERT INTO command wrong by using the variables :ORDERNR and :BLADNR

I'm not sure is that an error and is this the solution for your problem but use ':' before the variables when you retun values in them.
What is the exact error message?

the error is
Statement #3:
invalid request BLR at offset 789
undefined message number

I'm sure that the :OrderNr in the INsert into command create the error because when I change tis to 0, everything works fine

Is the data type the same in all tables as the type in the trigger?

Yes, I cheked this.