Dynamic Population of List Item Not Working

Question

My requirement is to have 1 list item that is populated based on the value selected for a second list item. in the when-list-changed trigger of the second list item, i make a call to a procedure (code below). This seems to not like any of the clear_list or populate_list. the list item type is poplist. i set the class to list. if i use populate_list in when-new-form-instance, there's no problem. PLEASE HELP. When can't I populate list using a procedure??
ERROR: frm-40734 internal error pl sql error occurred
PROCEDURE Refresh_List IS
v_rg_name VARCHAR2(40) := 'RGTEST';
v_rg_id RecordGroup;
v_sql varchar2(2048);
problem EXCEPTION;
status number;
list_id item;
BEGIN
     list_id := Find_Item('BLK_TEST.LST_TEST');
v_sql:='select column_name from sys.all_tab_columns where table_name=''testtable''';
               v_rg_id := Find_Group( v_rg_name );
               IF Not Id_Null(v_rg_id) THEN
                         DELETE_GROUP( v_rg_id ) ;
               End if;
               clear_list(list_id);
               v_rg_id := Create_Group_From_Query( v_rg_name, v_sql ) ;
               status := Populate_Group( v_rg_name );
               POPULATE_LIST(list_id, v_rg_id);
               POPULATE_LIST('BLK_TEST.LST_TEST', 'RGTEST'); also tried this.
               if status <> 0 then
                         raise problem;
               end if;
          EXCEPTION
               WHEN problem THEN
                         message('problem.');
               WHEN others THEN
                         message('tooto');
END;

Answer 1

Thanks for the response. I've tried this example too and it still doesn't like the things mentioned in previous post. In addition, it doesn't like SET_RECORD_PROPERTY(:system.cursor_record,'EMP',status,new_status); I get the same sort of error. The form compiles fine though.
Background on form:
this form was created to allow users to dynamically build an update statement. On this form are a number of list items and text boxes that are not populated from a database. So the datablock doesn't retrieve values from the database and the only updating that will be done is when the user clicks an "update" button to execute the sql statement that is built. Could this issue I'm having be related to the way i designed my datablock and items? When the user selects an item from one of the list items, the record status goes to "Changed". So I assumed my issue was because of this and thought the set_record_property statement would help...but that is generating the same error. what am i missing? if i look at the index value of the record group after create_group_from_query, it is -1. after populate_group, it is still -1. should it still be -1?? any help is greatly appreciated.