----------------------------Original message----------------------------
Hi there.  I think it depends on the individual show.  Some hits can be
renewed for years at a time, "Northern Exposure" for example was renewed for
three I believe.  Others get picked up for only one season, or sometimes even
ten or less episodes.  Basically, from what I understand, there is no written
rule for this type of thing.....Sorry to be of so little help..
 
Sarah