Saved by the Bell is an American television sitcom that aired on NBC from 1989 to 1993. The series was a retool of the Disney Channel series Good Morning, Miss Bliss. The show follows the exploits of a group of friends and their principal, and although the series primarily showcases light-hearted comedic situations, it occasionally touches on serious social issues, such as drug use, driving under the influence, homelessness, divorce, death, and environmental issues. This made Saved by the Bell a precursor to later shows that introduce young audiences to critical moral dilemmas. Saved by the Bell stars Mark-Paul Gosselaar, Dustin Diamond, Lark Voorhies, Dennis Haskins, Tiffani-Amber Thiessen, Elizabeth Berkley, and Mario Lopez. Saved by the Bell was named one of the "20 Best School Shows of All Time" by AOL TV. The show's popularity spawned two spin-off series to follow: Saved by the Bell: The College Years, a prime time series that follows several of the original characters to college, and Saved by the Bell: The New Class, a Saturday morning series that follows a new group of students at Bayside High School. The series also spawned two TV movies and a short-lived comic book series. Saved by the Bell also aired in Australia on Channel Seven, and from 1990 until 2004 on Nickelodeon. Reruns have aired in local syndication and on MTV2.