Should use pop-up to warn when closing tab

[pdg137]

There's a feature that many sites use to avoid accidental tab closing; I think it's JavaScript's beforeunload event. BesoGo should use this to generate a pop-up and give the user one last chance to avoid lost work.

[yewang]

I think another way to handle the underlying issue (of avoiding lost work) would be to cache the game tree state (maybe just dumped into SGF format) into local storage.

[ParmuzinAlexander]

It's easy to do it yourself. Add

window.onbeforeunload = function() {
	return true;
};

to besogo.js
But I noticed that it only disturb because I never accidentally click on close.