<?php
$ga="UA-5985675-2";
if(array_key_exists('ga',$_GET) && !empty($_GET['ga'])) $ga=$_GET['ga'];
header('Content-type: text/javascript');
?>
var _gaq=[['_setAccount','<?php echo $ga?>'],['_trackPageview']];(function(d){var g=d.createElement('script'),s=d.scripts[0];g.src='//www.google-analytics.com/ga.js';s.parentNode.insertBefore(g,s)}(document));