title: Bring data without postback on click of link
body: <p>I was thinking to implement fetching of data with ajax request on click of a link. I know how to work with $.ajax and other xhr request methods. I wanted to know some infromation on the following case. I went to <a href="http://www.facebook.com/?sk=welcome" rel="nofollow">http://www.facebook.com/?sk=welcome</a>
  and then I clicked "Find Friends" I noticed the url changed to <a href="http://www.facebook.com/?sk=ff" rel="nofollow">http://www.facebook.com/?sk=ff</a> and the data in the right hand side was refreshed(without postback) and my friends were loaded. The strange thing I noticed was that no XHR request was logged (I was looking with FireBug console) which I expected to be. How does FB do that with any XHR request? <strong>Does FB uses Iframe for it, if not, then how does it refreshes a section of page with fresh data without postback without some XHR request (in this case)</strong>.</p>
  
  <p>How client can call server's data without postback, without iframe and without some ajax call?</p>