Use PHP To Detect An Ajax Request

Here is a quick PHP snippet that you can use to tell if the request coming to the page is from a form or from an Ajax request.
Where a page is being accessed by AJAX it will post data using XML, PHP can then pick up on the HTTP request and see what the return is expecting. For this you just need to use the PHP server variable and grab the parameter HTTP_X_Requested_With.
For this you just need to use the PHP server variable and grab the parameter HTTP_X_Requested_With.

$_SERVER['HTTP_X_REQUESTED_WITH']

if(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && !empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest')
{
From Ajax

}else{
Not Ajax

}