Thanks
But I want it other way round
NIFTY-1 to NIFTY18AUGFUT now
and even after changing and saving Future=
(keeping blank, not giving NIFTY18AUGFUT but still NIFTY-I )
May be it will work on a system restart,
but what I am missing now, that it is not changing, NIFTY-1 to NIFTY18AUGFUT