<div class="one">hi</div>
<script type="text/javascript" src="app.js"></script>
<?php
$maks = $_POST['data'] . ' Maksim';
echo $maks;
$(function() {
var data = $('.one').html();
$.ajax({
type:'POST',
url: 'form.php',
data: {data: data},
success: function(data){
alert(data);
}
});
});
https://habrahabr.ru/post/336708/