Who played Kelly Kapowski in 'Saved by the Bell'?

In which TV series is Newman a main character? Who played Zack Morris in 'Saved by the Bell'? Who played A.C. Slater in 'Saved by the Bell'? In which TV series is A.C. Slater a main character? In which TV series is Kelly Kapowski a main character? Who played Screech Powers in 'Saved by the Bell'? In which TV series is Screech Powers a main character? Who played Steve Urkel in 'Family Matters'?