Complex sentence: The Showgram has had a variety of interns over the years and used to be called the "Bob and Madison Showgram" until co-host Madison Lane left to do her own morning gig at sister station WRSN in 2004.
Split into simpler sentences: The Showgram has had a variety of hosts over the years; and during the tenure of Madison the show was refered to as "The Bob and Madison Showgram". The show aired until co-host Madison Lane left to start her very own morning show at sister station WRSN in 2004.