Casio CZ/ VZ/ FZ - Pro Series

hi,

there's mention in the powerplay vz pdf about disabling/enabling 
envelope steps..  for the life of me, i cannot figure out how this is 
done on the vz-10m.  i've pretty much figured out all the other 
parameters and how to navigate my way around all the menus, but i 
can't seem to figure this one out.  any help?  thanks.