added disconnection for clearing hear the world stream when user disconnects....

added disconnection for clearing hear the world stream when user disconnects. mit bi erreneous if more than 2 clients are connected

app.js

@@ -28,6 +28,7 @@ io.on('connection', function(socket){
     io.sockets.emit('updateUserCount', Object.keys(io.engine.clients).length);
     socket.on('disconnect', function(){
       io.sockets.emit('updateUserCount', Object.keys(io.engine.clients).length);
+      io.sockets.emit('clearExternalData');
     });
   	console.log('a user connected');
   	socket.on('bpm', function(newBpm){

public/client.js

@@ -28,7 +28,10 @@ $(function(){
     iosocket.on('updateExternalGrid', function(data){
         //playExternalSound(data));
         externalGrid = data;
-        
+    });
+
+    iosocket.on('clearExternalData', function(){
+        externalGrid = null;
     });
 
     iosocket.on('updateUserCount', function(userCount){