Here's how I call this code ... it's my wrapper for Ajax:

var ajax = new XMLHttp();

When I run that, I get the error in Firefox's Error Console that ajax.get is not a function. So I've checked this code ten times and I see nothing wrong. It's almost copied exactly from an example I saw online, and that example works (so says the author, it's from About.com). Here's all the pertinent javascript code:

function XMLHttp() {
    if (window.XMLHttpRequest) { // If we have a Gecko browswer?
        return new XMLHttpRequest();
    } else if (window.ActiveXObject) { // IE is more difficult ...
        var avers = ["Microsoft.XmlHttp", "MSXML2.XmlHttp", "MSXML2.XmlHttp.3.0",  "MSXML2.XmlHttp.4.0", "MSXML2.XmlHttp.5.0"];
        for (var i = avers.length -1; i >= 0; i--) {
            try {
                httpObj = new ActiveXObject(avers[i]);
                return httpObj;
            } catch(e) {}
    // And what if the the browser sucks?
    alert("Your broswer is too old. Consider upgrading!");

XMLHttp.prototype.get = function(url, element) {
    this.open('GET', url, true);
    this.onreadystatechange = function() {

XMLHttp.prototype.processRequest = function(element) {
    if (this.readyState == 4 && this.status == 200) {
        findElement(element).innerHTML = this.responseText;

function findElement(target) {
    var targetElem = document.getElementById(target);
    if(!targetElem) {
        targetElem = getElementsByClassName(document, "*", target);
    return targetElem;

The XMLHttp() function works fine, as I can use ajax.open and ajax.onreadystatechange. But I can't use ajax.get ... I've tried calling the XMLHttp() function without "new" before it ...

I'm lost ... what's wrong with that code?

11 Years
Discussion Span
Last Post by nloding

The only problem I can see on the face of it is that you defined the get function as taking two parameters and you're only calling it with one parameter...

That doesn't usually cause a problem (Javascript is quite forgiving), but it's worth checking.


I have tried that actually, I saw that last night. I plugged in the ID of the <div> I wanted to update, using both single, double, and no quotes. To no avail. I still get "ajax.get is not a function".

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