Setting a date field to a default value if it's left blank by the user?

Question

I want to set a date field by default to 31/12/2499 if the user doesn't input anything. I want to do this in WHEN-VALIDATE-ITEM trigger .
How should my code be like please ? Is it something similar to this :
IF :HS_HEADS.DT_TO IS NULL THEN
     HS_HEADS.DT_TO =:'31/12/2009';
ELSIF
     ALERTS.STOP_ALERT('Date must be greater than or equal to system date', choice);
     RAISE FORM_TRIGGER_FAILURE;
END-IF;
Thanks.

Answer 1

Isn't it too late to set default value in WHEN-VALIDATE-ITEM? It will not fire if user doesn't input anything
I would set properties of HS_HEADS.DT_TO as following:
Data Type = Date
Initial Value = 31/12/2009
Format Mask = DD/MM/YYYY
And in WHEN-VALIDATE_ITEM just validate that date is not less then SYSDATE
IF :HS_HEADS.DT_TO < trunc(SYSDATE) THEN
-- alert
RAISE FORM_TRIGGER_FAILURE;
END IF;BTW, why do you default to hard-coded 31/12/2009? Is your application only good until end of the year?