When-validate-item Oracle error

Question

Hello,
I am using oracle forms 10g and database 9i.
In a form I have written the following code for doing the validation of the items.
<pre>
PROCEDURE MANDATORY_FIELD(FIELD_NAME VARCHAR2 DEFAULT NULL) IS
V_FIELD_NAME VARCHAR2(65) := FIELD_NAME;
BEGIN
IF V_FIELD_NAME IS NULL THEN
          IF NAME_IN('SYSTEM.CURSOR_ITEM') IS NULL THEN
          message('Field must be entered.');
          END IF;
ELSE
          IF NAME_IN('V_FIELD_NAME') IS NULL THEN
          message(' Field must be entered.');
          END IF;
END IF;
END MANDATORY_FIELD;
</pre>
When I am calling the procedure MANDATORY_FIELD(block.item_name) from the trigger WHEN-VALIDATE-ITEM in tiem lebel I am getting error "FRM-40105, Unable to resolve reference to item V_FIELD_NAME".
Any suggestion why it is happen and how to overcome from it.(Other then handing the error).
Regards
SUN

Answer 1

Why would v_field_name ever be null? It's as if you're telling forms that there is a required field somewhere but you don't know which one it is!
How about this for a generic validation process:
procedure check_condition(p_condition in boolean, p_errmsg in varchar2) is
begin
  if p_condition then
    message(p_errmsg);
    message(p_errmsg);
    raise form_trigger_failure;
  end if;
end;Then in your when-validate-item trigger you can have
check_condition(:block.item is null, 'Please enter the <whatever field is called>.');or
check_condition(:block.some_date < :sysdate, 'Please enter a future date.');etc