title: throw err in node (in CSS)
body: <p>when i try to run nodejs, there is an error in "throw er;" in the "css" part, but it doesn't exist. Someone can see the error?</p>
  
  <pre><code>var http = require('http'),
  fs = require('fs');
  
      http.createServer(function(req, res) {
  
              fs.readFile('./index.html', function (err, data) {
                  if (err) { throw err; }
                      res.writeHeader(200, {'Content-Type': 'text/html'});
                      res.write(data);
                      res.end();
  
              });
  
  
              fs.readFile('./main.js', function (err, data) {
                  if (err) { throw err; }
                      res.writeHead(200, {'Content-Type': 'text/javascript'});
                      res.end(data);
                      res.end();
              });
  
              fs.readFile('./style.css', function (err, data) {
                  if (err) { throw err; }
                      res.writeHead(200, {'Content-Type': 'text/css'});
                      res.write(data);
                      res.end();
              });
  
      }).listen(8000);
  </code></pre>