Cursor read-Only Error

     
The following code gives an error of "cursor is read only".
The problem is caused by the order by clause of the Cursor select definition.
Is there a fix for this scenario.
Typically the table will contain records with Batch values of 100,120, 139, 200 ..etc and I wish to
update the Batch values as 10,20,30,40 ..etc  


                declare @n smallint
      declare @batch smallint
      DECLARE cursor1 CURSOR SCROLL_LOCKS
      FOR
      SELECT     Batch
      FROM       JazzCarryOver
      order by Batch FOR UPDATE OF Batch;

      OPEN cursor1;

        set @n = 10
      FETCH NEXT FROM Cursor1 into @batch
-- re number Batch in ascending order
      WHILE @@FETCH_STATUS = 0
      BEGIN
            UPDATE JazzCarryOver
            SET Batch = @n
            WHERE CURRENT OF cursor1;
            set @n = @n + 10
            FETCH NEXT FROM Cursor1 into @lotnum,@batch
    END;
      CLOSE Cursor1;
      DEALLOCATE Cursor1;