trigger with check integer column

[pashki]

I have create trigger:

CREATE TRIGGER TR
NO CASCADE
BEFORE INSERT ON T
REFERENCING NEW AS newrow
FOR EACH ROW MODE DB2SQL
WHEN (newrow.id = null)
BEGIN ATOMIC
set newrow.id = nextval for SAMPLE.sequ ;
END

But, write error with type. Column 'id' is integer and primery key.
If ID is then entered id, unless it gets sequence. but I can not do a check on value.

Please help me.
Thanks

[pashki]

i'm find vote this problem

[pashki]

CREATE TRIGGER TR
NO CASCADE
BEFORE INSERT ON T
REFERENCING NEW AS newrow
FOR EACH ROW MODE DB2SQL
WHEN (newrow.id = null)
BEGIN ATOMIC
set newrow.id = nextval for SAMPLE.sequ ;
END

CREATE TRIGGER TR
NO CASCADE
BEFORE INSERT ON T
REFERENCING NEW AS newrow
FOR EACH ROW MODE DB2SQL
WHEN (newrow.id is null)
begin atomic
set newrow.id = nextval for sequ;
end