Calling .Net webservice with Jquery is causing woe when trying to post data

I think the webservice expects the parameter json to be set. Try this AJAX call :

var data = {'name':'niall'};$.ajax({    type: "POST",    url: "/WebServices/BasketServices.asmx/AddItemToBasket",    data: "json=" + JSON.stringify(data),    contentType: "application/json; charset=utf-8",    dataType: "json",    success: OnItemAddedSuccess});

where JSON.stringify() is a method like the one found in the "official" implementation : http://json.org/js.html

The solution above did not work for me. So instead i did the following.1.) make sure the the javascript object-properties (here ID and Quantity) do have the same name and the same type (in this case number == int) as the parameter of your webservice2.) do not wrap the object into a Data Transfer Object (DTO), but instead just stringify themThanks goes to Yasin Tarim which gave the hints i needed to get it working

// javascript objectvar cartItem = {"ID": 123, "Quantity": 2}$.ajax({    type: "POST",    url: "/WebServices/BasketServices.asmx/AddItemToBasket",    data: JSON.stringify(cartItem),    contentType: "application/json; charset=utf-8",    dataType: "json",    success: function (data) { OnSuccess(cartItem, data); },});

    // ASMX Server Side Code    [WebMethod(Description = "Add item to ShoppingCart")]    [ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)]            public string AddItemToBasket(int ID, int Quantity)     {                    CartItem cI = new CartItem();        cI.iD = ID;        cI.qty = Quantity;        CartItem.SaveToDatabase(ci);        return "foo from Webservice - it worked";    }

This should work. You should pass json as a string, with a parameter name 'json' (which is the same as parameter name in your web method.

data: "{json: '{\'name\':\'niall\'}'}",