Passing parameters accross multiple forms

Question

I want to call formB from formA and pass parameters while doing it.
BLOCK2 in formA contains a textitem named EMPID and I wand to pass the value in it to textitem named EMPID in BLOCK4 of formB.
I created a parameter list and added items and values to it.
I use call_form with the required entries to call formB.
---- Code used by me for creating parameter in formA and calling formB starts here ------
DECLARE
     PLID PARAMLIST;
BEGIN
     PLID := GET_PARAMETER_LIST('PL');
     IF NOT ID_NULL (PLID) THEN
          DELETE_PARAMETER ('PL','P_EMPID');
     ELSE
          PLID := CREATE_PARAMETER_LIST('PL');
     END IF;
     ADD_PARAMETER('PL', 'P_EMPID', TEXT_PARAMETER, :BLOCK2.EMPID);
     CALL_FORM('C:\Project\formB', HIDE, NO_REPLACE, NO_QUERY_ONLY, 'PL');
END;
----------------------- Code ends here ---------------------------------
I added a parameter in object navigator/parameters and named it P_EMPID of type Char and length 11 (b'coz, :BLOCK2.EMPID is Varchar2(11))
Also, I have written the following code in formB:
:BLOCK4.EMPID := :PARAMETER.P_EMPID;
I have written this code in the following three places of formB:
1) WHEN-NEW-FORM-INSTANCE --> form-level trigger
2) PRE-FORM --> form-level trigger
3) PRE-QUERY --> block-level(BLOCK4) trigger
Additionally, I also tried using GET_PARAMETER_ATTR to get the parameter value in WHEN-NEW-FORM-INSTANCE of formB. It is as follows:
-------- Code for retreiving parameter in WHEN-NEW-FORM-INSTANCE of formB starts here ---------
:BLOCK4.EMPID := :PARAMETER.P_EMPID;
DECLARE
     P_EMPID VARCHAR2(11);
     PLID PARAMLIST;
     PARAM_TYPE NUMBER;
     CURRENT_VALUE VARCHAR2(11);
BEGIN
     PLID := GET_PARAMETER_LIST('PL');
     IF NOT ID_NULL (PLID) THEN
          GET_PARAMETER_ATTR('PLID','P_EMPID',PARAM_TYPE,CURRENT_VALUE);
          :BLOCK4.EMPID := CURRENT_VALUE;
     END IF;
END;
----------------------- Code ends here ---------------------------------
In spite of all the above, when formB tries to start, I get FRM-47023 No such parameter named P_EMPID exists in form formB
What do I need to do?
Thanks,
Preethi

Answer 1

I suppose you shouldn't try to extract parameter value from parameter list in WHEN-NEW-FORM-INSTANCE as Forms do it for you. Just use :parameter.P_EMPID. Of course, you may also use global variable or some package variable (if sharing library datf), or record group, created with GLOBAL_SCOPE.