Php script performing differently on Chrome as oppose to IE & FF - php

Question

I have a php script that returns posts from tumblr. The posts are determined by a number. The number is incremented by 1 every time I hit the go button on my website. This seems t work perfectly in Firefox and Internet explorer but not chrome.
My code:
My index.php file.
<?php
session_start();
$_SESSION['views'] = 0;
?>
<?php include 'blogFunction.php';?>
<script type="text/javascript">
function doSomething()
{
$.ajax({ url: '/blogFunction.php',
data: {action: 'test'},
type: 'post',
success: function(output) {
document.getElementById("blog").innerHTML = '';
document.getElementById("blog").innerHTML = output;
}
});
}
</script>
<div class ="blog" id = "blog"></div>
my blogFunction.php
function blogreturn(){
$request_url = "http://retrovate.tumblr.com/api/read?type=posts";
$xml = simplexml_load_file($request_url);
$a = $_SESSION['views'];
$b = $a+4;
echo "A = ".$a;
echo "B = ".$b;
$_SESSION['views'] = $_SESSION['views']+ 1;
for ($i = $a; $i <= $b; $i=$i+1) {
echo '<h2>'.$xml->posts->post[$i]->{'regular-title'}.'</h2>';
echo '<br>';
echo $xml->posts->post[$i]->{'regular-body'};
echo '<br>';
echo '<br>';
}
}
My website can be foundhere to test.
The website should also print the values of A and B under the 'Go' Button.
Any idea why it doesn't work in chrome. Thanks in advance!