Have a nice day, indeed. Getting a jump on the fall season, Fox last week unveiled its most high-profile new sitcom — That ’70s Show (7th) — to positively groovy ratings. The controversial coming-of-age comedy (complete with a scene of the teen cast literally going to pot) not only premiered in the top 10, it also built on its Sunday lead-in, an original episode of The Simpsons (12th) — something no other debuting Fox comedy has ever done. Viewers weren’t so high on Fox’s other new Sunday-night sitcom, Holding the Baby (80th), which finished last in its time slot and failed to hold the audience amassed by its World’s Funniest! (70th) lead-in. Maybe they should dress the tyke in bell-bottoms.