a former trader at the french bank societe generale was convicted today on all counts, in one of history's biggest trading frauds. jerome kerviel was sentenced to three years in prison, and he was ordered to repay the bank a staggering $6.7 billion in damages. defense lawyers promised to appeal. they said, at his current salary, it would take kerviel more tn 175,000 years to pay the damages. the u.s. supreme court will decide how far the government may go in background checks of employees. the court today heard a case involving private contractors working for nasa. they oppose having to give personal information, including medical history and past drug use. the outcome could have far- reaching effects, because the same employment questionnaires are used throughout the federal work force. hungary declared a state of emergency after a torrent of toxic sludge from an aluminum plant tore through several towns. the death toll rose to four, with 120 injured. the reddish mud burst through a containment reservoir yesterday, and gushed down roads, pushing cars out of its way. the sludge covered ent