AJAX Ready State stuck on 1

Hi I can see this has been discussed but after perusing the issues/answers I still don't seem to be able to get even this simple AJAX call to bump out of ready state 1.

Here's the Javascript I have:

<script language="javascript" type="text/javascript">
var request;

function createRequest()
{
   try 
   {
      request = new XMLHttpRequest();
   }   catch (trymicrosoft) {
   try {
      request = new ActiveXObject("Msxml2.XMLHTTP");
   } catch (othermicrosoft) {
      try {
         request = new ActiveXObject("Microsoft.XMLHTTP");
         } catch (failed) {
           request = false;
         }
     }
 }
if (!request)
   alert("Error initializing XMLHttpRequest!");
}
function loadClassesBySchool()
{    
     //get require web form pieces for this call
 createRequest(); // function to get xmlhttp object
 var schoolId = getDDLSelectionValue("ddlSchools");   
 var grade = getDDLSelectionValue("ddlGrades");

     var url = "courses.php?grades=" + escape(grade) + "&schoolId=" + escape(schoolId);

 //open server connection
 request.open("GET", url, true);

 //Setup callback function for server response

   //+++read on overflow that some fixed the issue with an onload event this simply had
   //+++the handle开发者_开发技巧 spitback 2 readystate = 1 alerts

     request.onload = updateCourses();

     request.onreadystatechanged = updateCourses();

 //send the result
 request.send(); 
}

function updateCourses()
{

    alert('ready state changed' + request.readyState);

}

function getDDLSelectionValue(ddlID)
{
    return    document.getElementById(ddlID).options[document.getElementById(ddlID).selectedIndex].value;   
  }

</script>

The PHP is HERE just a simple print which if i navigate to in the browser (IE/Chrome) loads fine:

<?php
    print "test";
?>

I'm quite new at this but seems like I can't get the most bare bones AJAX calls to work, any help as to how work past this would be greatly appreciated.

All I get out of my callback function 'updateCourses' is a 1...

Well after more digging I actually gave up and switched over to jQuery which should for all intents and purposes be doing the EXACT same thing except for the fact that jQuery works... I was just less comfortable with it but so be it.

Here's the jQuery to accomplish the same:

function loadCoursesBySchool(){

    var grades = getDDLSelectionValue("ddlGrades");
    var schoolId = getDDLSelectionValue("ddlSchools");

    jQuery.ajax({   
        url: "courses.php?grades=" + grades + "&schoolId=" + schoolId,  
        success: function (data) {  
            courseDisplay(data);    
        }   
    }); 
}

function courseDisplay(response)
{
    //check if anything was setn back!?
    if(!response)
    {
        $("#ddlCourses").html("");
        //do nothing?   
    }
    else
    {
        //empty DLL
        $("#ddlCourses").html("");
        //add entries
        $(response).appendTo("#ddlCourses");
    }       
}