In florida,how long do you have to be married in order to collect alimony from your spouse after the divorce?

My father in law is a know it all and thinks he is right about everything. he told me that you have to be married for 20 years and your spouse could not hold a job at all through out the marrage in order for her to collect alimony. my exs parents went through a divorce some three years ago and his mother told me that they were only married for five years. what are the requirment to be able to collect alimony.