Parameters of ajax request don't change - php

Question

I' m using cms ModX and want to send Ajax request to server using post method. The problem is that the post data of the second, the third and so one requests doesn't change and remains the same as in the first request.
To clarify the situation I provide the following example.
The javascript is the following:
var reqCount = 0;
$(document).ready(function () {
$(window).scroll(function() {
var dataToPost = {'reqCount' :reqCount};
$.ajax({
url: 'http://example.com/ajaxTest',
method: 'POST',
data: dataToPost,
dataType:"json",
success: function(data){
ajaxCountFromServer = data['ajaxCount'];
reqCount=reqCount+1;
}
});
}
}
Also I created resource with address http://example.com/ajaxTest in Modx with the code, running the snippet:
[[getAJAX]]
getAJAX snippet is the following:
<?php
if ($_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest') {
$reqCount = $_REQUEST['reqCount'];
$json_obj = array("ajaxCount" =>$reqCount);
return json_encode($json_obj);
}
?>
So, after the first scroll reqCount=0, it's passed to server and after the server responses(success callback) ajaxCountFromServer=0 and reqCount=1. There all works well.
However, after the second scroll reqCount=1 and after the server response ajaxCountFromServer=0,but it should be 1.
How to fix it?

Answer 1

The solution is quite simple. In the page customizing of the resource http://example.com/ajaxTest, where snippet getAJAX is called, I just unchecked the checkbox "Cacheable".

Answer 2

The correct way to do it is
[[!getAJAX]]
The snippet is not cached now