I need to know how is it possible using AJAX to navigate between pages like Facebook. When I click a link in Facebook the url in address bar changes and the main content area is reloaded with new content but the navigation list on left, header on top and chat on left side remain intact. It appears that those sections are not reloaded. How this become possible when the address bar changes? please ,if possible give a small example.
You can use libraries such as history.js coupled with ajax calls. This library dynamically modifies the URL as you are clicking around the site. The library is available at https://github.com/browserstate/History.js. And a great demo is available at http://rypit.me/demos/isotory/tutorial/history.js.html