what is use of keys.js

[wistubbs]

Great program but one of my issues is wanting to get it to run with nginx. Under nginx there are a lot of complaints about missing /js/keys.js . Interestingly using apache, it doesn't complain about keys.js .
But in fact there is not a /js/keys.js in the distribution.
For example fhh.html asks for "../js/keys.js" but as I said it is not there.
The problem I was having under nginx is it not being able to load saved data.