Under what conditions, the approach ref page will show the ils(vor and crs)?
I did read FMS manual. The manual said, in Approach Ref page, ILS(VOR and CRS)will be blank prior to entering a destination runway in the active route. what means the exact destination? and active route?
If I trun back to the departure airport, I set depart airport as arrival in Leg page and chose runway in Dep/Arr page .
As manual said, I did not change the Rout page destination. is that also a active route destination? why I can not get ILS( vor and crs) in the approach ref page?So I have no way to capture the localizer
if I did wrong, what is the right way?

thanks