There is a flag pattern in Bank Nifty...Going above 17450--17470 zone -one should look to buy with small target of 17540 & sustaining above 17550 can take it above 17660 previous high....be clear ..take long only above 17470 --which polarity reversal zone...A & B were support & C--formed resistance so crossing 17470 will give clue that Bank Nifty wants to move up....Going below previous low will open weakness in the instrument. Regards, Abhishek H.Singh