[jQuery] Ajax Dot Net Plugin

[Jon]

I'm trying to get the ajax dot net plugin working and failing
miserably.

I've added the service - both manually and by dragging the example
files into my solution.
I've copied the hello world function from the example solution and
added it to the service and the jquery for it.
I've copied the system.serviceModel into my web.config. Again, i've
tried using the default one created when adding the service to the
solution and i've copied it across from the example solution.

But no matter what i do i can't get the ajax to work.

//      Hello World
    $.ajaxDotNet(url + "HelloWorld", {
        verb: "GET",
        success: function(obj) {
            obj = obj.d;
            alert('Hello World');
            $(".HelloWorld").text(obj);
        },
        error: function() {
            alert('Hello Error');
            $(".HelloWorld").text("Error");
        }
    });

Every time i run it i just get the Hello Error alert.

Does anyone know if i'm missing something essential? Am i making a
stupid error?

Please help, i'm dying to get this plugin working! And if i can't get
this working does anyone else has any experience with JQuery and Dot
Net and might be able to point me to a solution?