Why won't this work!?

<script type="text/javascript">
function loadXMLDoc()
{
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("myDiv").innerHTML=xmlhttp.responseText;
    }
  }
var somedata = "hi";
xhr.open("POST", "randompage.php");  
xhr.send(somedata);  
}
</script>

<h2>Using the XMLHttpRequest object</h2>
<div id="myDiv"></div>
<button type="button" onclick="loadXMLDoc()">Change Content</button>

I'm just trying to write 'hi' to 'randompage.php' when somebody clicks 'Change Content', but nothing happens... Grr...

When you go to the php page directly does it return 'hi'?

Nope, it's completely blank

With a AJAX POST request if you are sending data you need to send the data AND contentype headers.

http://www.w3schools.com/ajax/ajax_x...quest_send.asp