how to promt a message if a field is empty in oracle forms

How to prompt a message if field is empty in oracle forms i'm not sure if it works and the trigger i'm using is when-validate-item

begin
  if date = NULL then
    message('please enter issue date')
  else
    null;
  end if;
end;

From my point of view:

• you should edit field's properties and set the required property to yes and let Forms worry about it

• if you insist on reinventing the wheel, then don't just display a message as it is pretty much useless - user can ignore it. Raise an error, instead

  if :block_name.item_name is null then
      message('Please, enter issue date');
      raise_form_trigger_failure;
  end if;
  

  Put that piece of code into the WHEN-VALIDATE-ITEM trigger.