Dear Norman
Thank you very much. It works. As a matter of fact, the 'Required'
was grayed, but after I clear it, no more problems.
Using your information, I tryed to solv a second problem, but the
same logic did not work. I have a table which primary key is
generated by a before insert trigger:
BEGIN
IF (NEW.COR IS NULL) THEN
NEW.COR = GEN_ID(GEN_TABCOR_ID,1);
END

if I do not send a value to the field, I receive an error, because
the PK stays with no value at all. I tried to click the 'Computed'
field at Columnattributes tab, but the same error. Another tryal was
to mark 'Blank is null', to force the trigger to work. No solution.
You said the the default values are applied after a post, but a
before insert trigger would have to suplied a data.
Could you help me also in this matter ?
Thank you
Edison