Dynamic List Item And Error Frm -41331 (Can Not Delete Elements)

Dear brothers

I need to Create a Second List Item based on First List Item ,I already created the first one and I put the following code in the trigger WHEN_LIST_CHANGE of the first list item so I can create the second one

Declare
V number (5):=10;
Cursor c_dept is select distinct(BANK_NAME),BANK_NAME from BANK_INFO where BANK_province=:BQ.bank_PROVINCE;
Begin
For I in c_dept loop
Add_List_Element (' BQ.BANK_NAME',V,I.BANK_NAME, I.BANK_NAME);
V:=V+1;
End loop;
End;

But I need to delete the whole elements of the second list item so I can create another one based on the choosing value of the first list item, I tried to use DELETE_LIST but an error occurs FRM -41331 (can not delete the elements ) ….. can any one help to solve this problem ….. and thanks to you all ……… please answer me in arabic