Q:

ASP.NET webservice wish ajax, json, jquery and vb.net

I am tying out this tutorial, http://www.ezzylearning.com/tutorial.aspx?tid=5869127. 
It works perfectly.  What I am now trying to do is to host the aspx contents as html file.  This html file is hosted on my wampserver which is on my laptop.  The asp.net code hosted on my test server.  When I try to access, I get the following error, 
Resource interpreted as Script but transferred with MIME type text/html:      "http://201.x.x.x/testAjax/Default.aspx/AddProductToCart?callback=jQuery17103264484549872577_1346923699990&{%20pID:%20%226765%22,%20qty:%20%22100%22,%20lblType:%20%2220%22%20}&_=1346923704482".  jquery.min.js:4

Uncaught SyntaxError: Unexpected token <

I am not sure how to solve this problem.  
index.html code
    

    $(function () {
        $('#btnAddToCart').click(function () {
            var result = $.ajax({
                type: "POST",
                url: "http://202.161.45.124/testAjax/Default.aspx/AddProductToCart",
                crossDomain: true,
                data: '{ pID: "6765", qty: "100", lblType: "20" }',
                contentType: "application/json; charset=utf-8",
                dataType: "jsonp",
                success: succeeded,
                failure: function (msg) {
                    alert(msg);
                },
                error: function (xhr, err) {
                    alert(err);
                }
            });
        });
    });

    function succeeded(msg) {
        alert(msg.d);
    }

    function btnAddToCart_onclick() {

    }

</script>
</head>
<body>
        <form name="form1" method="post">
    <div>
    <input type="button" id="btnAddToCart"  onclick="return btnAddToCart_onclick()" 
        value="Button" />
</div>
</form>

aspx.vb
Imports System. Web. Services
Imports System. Web. Script. Services

<ScriptService()>
Public Class WebForm1
Inherits Page

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System. EventArgs) Handles Me. Load
    Session("test") = ""
End Sub

<WebMethod()>
<ScriptMethod(UseHttpGet:=False, ResponseFormat:=ResponseFormat. Json)>
Public Shared Function AddProductToCart(pID As String, qty As String, lblType As String) As String

    Dim selectedProduct As String = String. Format("+ {0} - {1} - {2}", pID, qty, lblType)

    HttpContext. Current. Session("test") += selectedProduct

    Return HttpContext. Current. Session("test").ToString()

End Function

End Class

A:

The reason for this is no matter how you specify the content-type of your ajax call, ASP.NET sends the request with Content-Type text/xml
A solution to this problem is available at:
http://bloggingabout.net/blogs/adelkhalil/archive/2009/08/14/cross-domain-jsonp-with-jquery-call-step-by-step-guide.aspx

