<div class="one">
<div class="one_1">RU</div>
<div class="one_2">EN</div>
</div>
$_SESSION['language']
<div class="mydiv">
</div>
<script src="//code.jquery.com/jquery-1.12.0.min.js"></script>
<script>
$.noConflict();
(function ($) {
$(function () {
$('.mydiv').on('click', function() {
$.ajax('set.php', {
'clicked_div' : 1
});
});
});
})(jQuery);
</script>
<?php
!empty($_REQUEST['clicked_div']) || exit('Див не нажат');
$_SESSION['your_data'] = 1;