The dollar gained versus major curencies  as U.S. employers added more jobs than forecast last month, boosting optimism the economy is withstanding higher taxes and lower government spending. The U.S. currency rose after the Labor Department reported the nation’s jobless rate unexpectedly fell to a four-year low of 7.7% and employment rose 236,000 last month after a revised 119,000 gain in January. The median forecast of economists projected an advance of 158,000. The jobless rate dropped from 7.9%.  Federal Reserve policy makers at their last meeting debated curtailing bond-buying that is seen as debasing the dollar, a move Chairman Ben S. Bernanke has opposed as he seeks to drive down unemployment to 6.5%.