title: How to create XMLHttpRequest
body: <p>I just need the clear explanation of the below code for creating <strong><code>XMLHttpRequest</code></strong>. </p>
  
  <pre><code>var xhr = false;
  if (window.XMLHttpRequest)
  {
      xhr = new XMLHttpRequest();
  }
  else if (window.ActiveXObject)
  {
      xhr = new ActiveXObject("Microsoft.XMLHTTP");
  }
  </code></pre>