Home/Limits not working

I am trying to set up home and limit switches on a mini mill running
TurboCNC and/or DeskNC and cant get either program to recognize them.
In both programs it is like the configuration menus for the I/o are
not accepting my changes . DeskNC will not allow me to edit an
existing machine file and setting up the limits is just, difficult and
dont work. TurboCNC I/O menu doesent respond correctly either, it
just disregards my changes, even after saving and re loading. Someone
mentioned a "Are home switches limit switches" prompt but I cant find
it anywhere on any menu. Any ideas whats up?
Thanks, Halfnutz