title: Why the callback function gets called twice for each request?
body: <p>Guys I am new to node js and this behavior is strange to me!
  In the code snippet below, </p>
  
  <pre><code>'use strict';
  var http = require('http');
  var numberOfRequests = 0;
  http.createServer(function (request, responce) {
      console.log('Request number ' + numberOfRequests + ' received!');
      responce.writeHead(200);
      responce.write("Here is responce to your request..");
      responce.end();
      numberOfRequests++;
  }
  ).listen(8080);
  console.log('listening ...');
  </code></pre>
  
  <p>for each </p>
  
  <pre><code>localhost:8080 
  </code></pre>
  
  <p>call at Chrome, the app writes twice onto console? e.i
  for a single 8080 call, it prints out:</p>
  
  <pre><code>Request number 0 received!
  Request number 1 received!
  </code></pre>
  
  <p>I am using Visual studio to run this node js app.</p>