Sou novo no Ajax e estou tentando desativar uma caixa de seleção se determinados itens estiverem selecionados em uma lista suspensa. Eu preciso passar o mlaId para o método GetMlaDeliveryType (int Id) no RecipientsController.cs.

Eu não sei exatamente como configurar a chamada do ajax na função javascript checkMlaDeliveryType (mlaId).

        //  MLA Add  disable express checkbox if delivery type is electronic
        $('.AddSelectedMla').change(function () {

            var deliveryType = checkMlaDeliveryType($('.AddSelectedMla').val());


            // disable express option if delivery type is Electronic
            if (deliveryType == "Mail") {
                $(".mlaExpressIndicator").removeAttr("disabled");
            }else{
                $(".mlaExpressIndicator").attr('checked', false).attr("disabled", true);
            }

        })

        // ajax call to get delivery type - "Mail" or "Electronic"
        function checkMlaDeliveryType(mlaId)
        {
            $.ajax({
                type: "GET",
                url: "/Recipients/GetMlaDeliveryType/" ,
                data: mlaId,
                dataType: ,
                success: 
            });

        }

RecipientsController.cs

    public string GetMlaDeliveryType(int Id) 
    {
        var recipientOrchestrator = new RecipientsOrchestrator();

        // Returns string "Electronic" or "Mail"
        return recipientOrchestrator.GetMlaDeliveryTypeById(Id);
    }

EDITAR:

Veja como o javascript final parecia que funcionou

//  MLA Add  disable express checkbox if delivery type is electronic
$('.AddSelectedMla').change(function () {

    checkMlaDeliveryType($('.AddSelectedMla').val());
})

// ajax call to get delivery type - "Mail" or "Electronic"
function checkMlaDeliveryType(mlaId)
{
    $.ajax({
        type: 'GET',
        url: '@Url.Action("GetMlaDeliveryType", "Recipients")',
        data: { id: mlaId },
        cache: false,
        success: function (result) {
            // disable express option if delivery type is Electronic
            if (result == "Mail") {
                $(".mlaExpressIndicator").removeAttr("disabled");
            } else {
                $(".mlaExpressIndicator").attr('checked', false).attr("disabled", true);
            }
        }
    });

}