added disconnection dialog to inform user

UI/index.html

@@ -190,6 +190,9 @@ function startGameSession() {
 	gameSession.onconnect = function () {};
 	gameSession.onclose = function (event) {
 		console.log(event);
+		popupDialog("connection_error","Connection Error!!!",false,messageDialog,"The server connection was closed!",function () {
+			window.location.search = ""; //reload page
+		});
 	};
 }