Node.js app.js not displaying HTML page but HTML code instead

Im having problem with my app.js in node not displaying my html page but my html code instead. I don't really know what to do so some help would be greatly appreciated. I would like to be able to load html, javascript and css from my public folder. This is my app.js code:

var http = require("http"),
    url = require("url"),
    path = require("path"),
    fs = require("fs")

http.createServer(function(request, response) {

var uri = url.parse(request.url).pathname
    , filename = path.join(process.cwd(), uri);

path.exists(filename, function(exists) {
  if(!exists) {
    response.writeHead(404, {"Content-Type": "text/plain"});
    response.write("404 Not Found\n");
    response.end();
    return;
}

if (fs.statSync(filename).isDirectory()) filename += 'public/index.html';

fs.readFile(filename, "binary", function(err, file) {
  if(err) {        
    response.writeHead(500, {"Content-Type": "text/plain"});
    response.write(err + "\n");
    response.end();
    return;
  }

  response.writeHead(200);
  response.write(file, "binary");
  response.end();
  });
 });
}).listen(process.env.PORT, process.env.IP);

console.log("Static file server running./\CTRL + C to shutdown");