Mmmm, I've got round the problem by doing:
echo "<body onload=" . $qt . "ajaxGenerate_Content('ajaxContent_generate','/Site/ajaxCon/" . $_GET['value'] . ".php?mthd=AJAX')" . $qt . ">";
Obviously with a case for if $_GET['value'] is not a recognised file, that way someone can link to a specific page with:
http://www.vasey.co.cc/Site/?value=Scripting