Several years ago during the dot-com passion, Manhattan lawyer John Kennedy sometimes wore a dark blue suit to meet potential Internet clients. But he soon realized that his conservative clothes were a strike against him before he even shook hands. So he began to do business in casual, open-shirt clothes. But now the tables have turned. Today Silicon Valley executives are the ones often coming out in suits. No wonder that Fortune 500 executives are dusting off their silk ties and pants. 'I would say there is a trend now toward a little more business dress,' said Kennedy. 'I find myself wearing suits more.' While there isn't a rush toward formal office wear, clothiers and executives say the workplace uniform. is heading that way. In many offices, men are wearing jackets, ties and pants more frequently than a year ago. Top women executives never went as casual as men, so the shift doesn't affect them as dramatically. 'Business casual' took several years to catch on. It started with casual Fridays, evolved to casual summers, then became casual everyday. Observers mention many factors driving the trend Internet companies helped lead the dress-down movement and other industries followed suit to attract workers. But with the collapse of many dot-corns, the relaxed look is becoming a style. to avoid. Moreover, as the economy stumbles, more people are hunting for jobs or trying to keep the ones they have, and appearance counts. U.S. President Bush wears a coat and tie in the White House office and expects his staff to dress 'professionally,' which some say sets a tone for the nation. 'Business casual' was prevalent several years ago because ______