Forms :: Use Cursor To Get Data From DB To Control Block

i want to use cursor to get data from db to "control block "(db item =no ) this data had where clause depend on item on other block

this my code :

declare
cursor get_sol is
select SOL_STEP,PROB_ID
from MI_SOLUTION
where PROB_ID=:MI_FORM_PROB.PROB_ID;
begin
go_block('control');
[code]......

when am using when_validate_item trigger error raise :

FRM-40737:Illegal restricted procedure next_record in when_validate_item

that's the trigger ? or how to solve ? in case of execute query in what trigger i will write the same code to get data in case of execute query by user .