In Coulum we have to mention the no. for control and also in report set we have put the budget defined in control field
For each set of books you can have only one current budget at a time.
Yes you can do so, reason being budget journal is not linked with your accounting period. Once you have open the budget period then you can book budget journal for that whole period.
One can define budgetary control for n number of years however, one year can have maximum of 60 fiscal periods.
Yes, you can disable budgetary control for a set of book by unchecking the 'Enable Budgetary Control' check box in the Budgetary control tab page of the define set of books window.