node.js + express + socket.io cannot load javascri

I'm developing an application and the server is currently set up and working well.

This is the index.html that shows when you access the server:

<!doctype html>
<html>
  <head>
    <title>Socket.IO chat</title>
  </head>
  <body>
    <script src="https://cdn.socket.io/socket.io-1.2.0.js"></script>
    <script type="text/javascript" src="./client.js"></script>
    <script type="text/javascript" src="./main.js"></script>
  </body>
</html>

However I get a 404 error "Failed to load resource: the server responded with a status of 404 (Not Found)" when importing those javascript files, which are in the same directory.

Here is my server code:

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

app.get('/', function(req, res){
  res.sendFile(__dirname+'/index.html'); // DO I NEED TO SEND THE OTHER FILES HERE ASWELL?
});

io.on('connection', function(socket){
  console.log('a user connected');

  socket.on('disconnect', function(){
    console.log('user disconnected');
  });

  socket.on('chat message', function(msg){
    console.log('message: ' + msg);
    io.emit('chat message', msg);
  });

});

http.listen(3000, function(){
  console.log('listening on *:3000');
});

Thanks!

If the HTML file is located in the same path as the scripts are, then use relative path like src = "main.js". If it still doesn't work, maybe it's Express' fault.

Add the codes below into your app.js:

app.use(express.static(__dirname + '/scripts'));

And the scripts can be accessed from the path relative to /scripts- e.g. main.js from http://yourdomain/script.js but not from http://yourdomain/scripts/main.js. Sorry for my English.