'Shrek Forever After' leads US box office

“Sex and the City 2” is on number two with $32.1 million collections, far below the $56.8 million opening weekend of its predecessor two years ago. Debuting at number three with $30.2 million was Disney's action tale "Prince of Persia: The Sands of Time", reports contactmusic.com.“Iron Man 2” is on fourth position and Russell Crowe starter “Robin Hood” on five