nifty is respecting an upward trend line. however as global cues are -ve, nifty is likely to give a gap down opening below the trend line. 17960-18000 is the critical support/resistance band. buy above 18040 with sl of 18010-18000 for targets of 18080/18150 sell below 17950 with sl @ 17970-17980 for targets of 17900/17855