Include jQuery based-on user's IE version.

jquery.php

<?php
/**
 * jQuery 2.x has the same API as jQuery 1.x, but does not support Internet Explorer 6, 7, or 8.
 * All the notes in the jQuery 1.9 Upgrade Guide apply here as well. Since IE 8 is still relatively common,
 * we recommend using the 1.x version unless you are certain no IE 6/7/8 users are visiting the site.
 */
function include_jquery() {
	if(preg_match('/(?i)msie [6-8]/', $_SERVER['HTTP_USER_AGENT'])) {
		// if IE<=8
		$version = '1.12.2';
	} else {
		// if IE>8
		$version = '2.2.2';
	}
	echo '<script src="//ajax.googleapis.com/ajax/libs/jquery/' . $version . '/jquery.min.js"></script>';
}