Help with triggers please

hey there.

here's the situation:
i'm updating the PROJECTID field of a row from the WORDPROCESSOR table . I would like all the records in this table , that have the same PARENTDOCUMENTID and PARENTDOCUMENTTYPE as the one of the updated record, to update their PROJECTID field with the value from the updated row.

i think the trigger should be put on the AFTER UPDATE event on the WORDPROCESSOR TABLE ..

if you think the trigger is a bad choice and i should have a stored procedure, or maybe the trigger should call a stored procedure.. please let me know...

here's what i rigged up ...(in Ms SQL Server )

BEGIN
DECLARE VARIABLE @DOCUMENTID AS INTEGER;

DECLARE VARIABLE RecordRow CURSOR FOR
SELECT DOCUMENTID FROM WORDDOCUMENTS
WHERE UPDATE.PARENTDOCUMENTID = WORDDOCUMENTS.PARENTDOCUMENTID
AND UPDATE.PARENTDOCUMENTTYPE = WORDDOCUMENTS.PARENTDOCUMENTTYPE;

OPEN RecordRow

FETCH NEXT FROM RecordRow INTO @DOCUMENTID

WHILE @@FETCH_STATUS = 0
BEGIN
UPDATE WORDDOCUMENTS
SET
WORDDOCUMENTS.PROJECTID = UPDATE.PROJECTID
WHERE
WORDDOCUMENTS.DOCUMENTID = @DOCUMENTID

FETCH NEXT FROM RecordRow INTO @DOCUMENTID

END

PS: i'm using firebird 2.0 (i think ... )

Kind thanks

Try to be shure at least of this, then post table structure and some sample data.