$_SERVER['HTTP_X_REQUESTED_WITH'] seemingly not available on PHP 5.1.6
<p>I've run into a problem on a server running php 5.1.6 - the code i use to detect ajax requests isn't working as the $_SERVER['HTTP_X_REQUESTED_WITH'] variable is missing from the $_SERVER array. The same code works fine on php 5.2 and in firebug i can see the headers include X-Requested-With XMLHttpRequest. Anyone know any more about this issue and how I can get round it? Thanks in advance.</p>
