Giving up all its initial gains, the Sensex at the Bombay Stock Exchange stood 20 points, or 0.1 percent in negative territory, at 20,082 in afternoon deals, a short while ago. Earlier in the morning, however, the Sensex had opened with a gain of 27 points, or 0.1 per cent, at a new two-year high of 20,129, on sustained buying by funds, amid strong third quarter corporate earnings. The 30-share Sensex had rallied over 280 points in the previous three trading sessions. The Nifty at the National Stock Exchange, which had breached the 6,100 level after two years, in morning deals, later stood 8 points in the red, at 6,074.Other Asian markets in Hong Kong, Singapore, South Korea, Taiwan, China, Indonesia and Japan were trading mixed, today.