Using the x-requested-with header to deliver different content to Ajax calls

Example

Load a document with Ajax.
Load the same document without Ajax.

Source Code

PHP

<?php if($_SERVER['HTTP_X_REQUESTED_WITH']=='XMLHttpRequest'){?>
This is content requested by Ajax.
<?php }?>

<?php if($_SERVER['HTTP_X_REQUESTED_WITH']==''){?>
This is the normal content requested in a browser
<?php }?>

Example

Source Code

PHP

jQuery