ORACLE TRIGGER question

I wrote the following trigger to alter the inserted data:

BEFORE INSERT ON PROPERTY
REFERENCING NEW AS nr
FOR EACH ROW
BEGIN
IF ( LENGTH ( RTRIM ( :nr.PROPERTY_DESCRIPTION ) ) < 0 ) THEN
TRANSLATE ( :nr.PROPERTY_DESCRIPTION, ' ', '0');
END IF;
END;
/

the same syntax works fine in sqlldr to replace blanks with 0's but trigger code fails.

Errors for TRIGGER INSERT_PROPERTY:

LINE/COL ERROR
-------- -----------------------------------------------------------------
3/12 PL/SQL: Statement ignored
3/12 PLS-00221: 'TRANSLATE' is not a procedure or is undefined

First: I don't think your IF statement will ever return true, because I cannot image a situation where the length of an String would be lower then zero (or did you mean > 0)

Second, I guess you need to write:
It's been a while since I wrote my last Oracle trigger, but as far as I can remember you have to assign the return value of your function call to something.

Yes I figured that out, the problem was with asignment