AJAX not working in Internet Explorer 9 - php

Question

This is my function:
<script type="text/javascript">
function loadXMLDoc() {
var x = document.getElementById("trazi_drzava");
var xmlhttp;
if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("trazi_grad").innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("GET", "gradovi.php?selected=" + x.value, true);
xmlhttp.send();
}
</script>
and I call it like this:
<select name="td" id="trazi_drzava" onchange="loadXMLDoc()">
<option value="">Država</option>
<?php
$sel_grad_arr=array();
$sel_grad_arr[]="<select name='tg' id='grad0'>
<option value=''>Grad</option</select>";
if($q=mysql_query("SELECT drzava_id,drzava FROM drzava")){
while($r=mysql_fetch_assoc($q)){
echo '<option value="'.$r['drzava_id'].'">'.$r['drzava'].'</option>';
}
}else echo mysql_error().__LINE__;
?>
</select><select name="tg" id="trazi_grad">
//code that ajax should load
</select>
It works fine with most browsers, but with Internet Explorer 9 it doesn't work at all. Anyone have any idea why?
UPDATE: I didn't manage to do this then. So I changed logic of working totaly. Thanks everyone for answers.

Answer 1

I know this is a very old question, but still, one with no actually correct answer....
The correct order of operations is:
Create your request object
open a connection
Set onreadystatechange listener
send request
You have steps 2 and 3 in the wrong order, which causes problems in certain browsers.

Answer 2

Maybe it's a cache problem. Parameter test set as a timestamp value, something like:
xmlhttp.open("GET","gradovi.php?selected="+x.value+"&t="+parseInt(new Date().getTime().toString().substring(0, 10)),true);
xmlhttp.send();
Regards!

Answer 3

Check how your request is sent to server. What does the double quotes look like? IE9, at least with jQuery, doesn't encode double quotes correctly according to this post:
Why does this jQuery Ajax call fail ONLY in IE9 (Even works fine in IE8 and IE7)

Answer 4

This is too late to answer but here's the solution that should solve this problem.
I had a similar problem this week. Change the
xmlhttp.open("GET", "gradovi.php?selected=" + x.value, true);
to
xmlhttp.open("POST", "gradovi.php?selected=" + x.value, true);
This solved my problem.
Check here:
This PHP script doesn't work in Internet explorer and Microsoft Edge but works in Chrome/Firefox/Safari/Opera