Webservice method not working

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
[System.Web.Script.Services.ScriptService]
//[ScriptService]
public class _Default : System.Web.Services.WebService {

    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString);

    SqlConnection conRecipes = new SqlConnection(ConfigurationManager.ConnectionStrings["constrRecipes"].ConnectionString);

    public _Default () {

     
         

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }
    [WebMethod]
    public string AddNominations()
    {
        return "Nomination Added Successfully";
    }

function CallService() {


        $.ajax({
            type: "POST",
            url: "_Default.asmx/AddNominations",
            data: "{}",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: Success,
            error: Error
        });
    }
    function Success(data, status) {
        $("#lblResult").removeClass("loading");
        $("#lblResult").html(data.d);
    }

    function Error(request, status, error) {
        $("#lblResult").removeClass("loading");
        $("#lblResult").html(request.statusText);
    }