Who played Michael Kelso in 'That '70s Show'?

Who played Charlotte York in 'Sex and the City'? In which TV series is Charlotte York a main character? Who played Eric Forman in 'That '70s Show'? In which TV series is Eric Forman a main character? In which TV series is Michael Kelso a main character? Who played Jackie Burkhart in 'That '70s Show'? In which TV series is Jackie Burkhart a main character? Who played Steven Hyde in 'That '70s Show'?