Display value from text file on website - php

Question

I am using AJAX to track the number of clicks of a button on my site and I would like to display that value on the page as well. Currently the tracking is working great and the number of clicks is being printed to a document called clicks.txt and I was wondering how I could go about reading the value from that text file and printing it to the page.
I tried searching SO and Google for an answer, but I guess I can't think of how to word it properly because the answers I have found so far have been unrelated to what I'm trying to do.
Here is the AJAX included in index.php
<script type="text/javascript">
function getXMLHttp()
{
var xmlHttp
try
{
xmlHttp = new XMLHttpRequest();
}
catch(e)
{
try
{
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{
try
{
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e)
{
return false;
}
}
}
return xmlHttp;
}
function MakeRequest()
{
var xmlHttp = getXMLHttp();
xmlHttp.onreadystatechange = function()
{
if(xmlHttp.readyState == 4)
{
HandleResponse(xmlHttp.responseText);
}
}
xmlHttp.open("GET", "counter.php", true);
xmlHttp.send(null);
}
function HandleResponse(response)
{
document.getElementById('ResponseDiv').innerHTML = response;
}
</script>
Here is the external PHP(counter.php) I am using to track the button clicks:
<?php
$clicks = file_get_contents("clicks.txt");
$clicks++;
$fp = fopen("clicks.txt", "w+");
while ( !flock($fp, LOCK_EX) ) {
usleep(500000); // Delay half a second
}
fwrite($fp, $clicks);
fclose($fp);
flock($fp, LOCK_UN);
?>
Thanks in advance!

Answer 1

$clicks = file_get_contents("clicks.txt");
echo $clicks;

Answer 2

If the page that the button exists on is a .PHP file, you can embed code similar to this directly on the page where you want it to be displayed:
<?php
$clicks = file_get_contents("clicks.txt");
echo $clicks;
?>