We have seen good momentum after some downside opening. CALL writer at 18000 level got trapped. Now 18000 is itself is immediate support for nifty and 18100 ,18200 target open as CALL writer have multiple position at diff strike. if 18100 break then we can see a good momentum tomorrow. further on the downside 17900 is strong support now. 18000 CE and 18100 CE will be good choice if 18100 broken and sustain above it. :)