Re-checking previously selected checkboxes

Question

Hi,
I've created a form with 2 canvases. On canvas2 there's a tabular list with check box for each row. From canvas 1 I call canvas 2 and return the check box selections from canvas2 to canvas1.
If I want to change the data selected, I can re-open canvas2. But when canvas2 opens, the saved selections are not reflected.For example: If row2 canvas2 was checked, then it is unchecked when canvas2 is re-opened.
I wrote a piece of code which re-checks the previously selected rows in canvas2, and verified in debug mode that it is working. However, after the trigger containing the code completes execution, the rechecking is lost and I am not able to identify why this is happening. Debug also does not let me trace where the execution flows after completing execution of the containing trigger.
Thanks.

Answer 1

For re-checking the checkboxes, I've written the code as follows:
     --RECHECK CHECKBOXES
     IF NVL (:BL_MESSAGE_MOVEMENT.DS_COUNT, 0) <> 0 THEN
          GO_BLOCK ('BL_USER');
          FIRST_RECORD;
          ST_POS := 1;
          CNTINSTR := :BL_MESSAGE_MOVEMENT.DS_COUNT;
          FOR I IN 1 .. CNTINSTR LOOP
               --GET USER CODE
               END_POS := INSTR (:BL_MESSAGE_MOVEMENT.DEST_USER_CODE,',', 1, I);
               LOCAL_USER_CODE := SUBSTR (:BL_MESSAGE_MOVEMENT.DEST_USER_CODE, ST_POS, END_POS-ST_POS);
               --FIND THE CODE
               --DBUG := :global.g_user_code;
               WHILE :BL_USER.USER_CODE is not null LOOP
        IF :BL_USER.USER_CODE = LOCAL_USER_CODE THEN
             :BL_USER.SELECT_FLAG := 1;
             EXIT;
        END IF;
        next_record;
/*        IF :SYSTEM.LAST_RECORD = 'TRUE' THEN
            :BL_USER.SELECT_FLAG := 1;
            EXIT;
        END IF;
*/             END LOOP;
               --PREPARE FOR NEXT LOOP
               ST_POS := END_POS + 2;
          END LOOP;
          END IF;     
          END IF;
END;