Word doesn't have an AutoSave. The supposed "autoSave" function is called
and acts as an AutoRecover, and only kicks in in time of crashes. For more
info, see here: http://word.mvps.org/faqs/general/AutomaticSave.htm
Learning to constantly hit control-S (cmd-S on Mac) every time you pause for
thought is the best idea, but for a macro you can install to avoid picking
up this habit, see here: http://www.gmayor.com/automatically_backup.htm