toggle form visibility on syubmit

Figure out how to hide the form on submit

I've tried several methods for binding `this` inside the component:

https://reactjs.org/docs/handling-events.html

But none work for me.

One option would be perhaps to try to ocnvert existing form a functional component w/ hooks & usestate -- bu thtat wil ltake a bit of work, don't have time for it now.  Oh well!